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Vestibulo‐Sympathetic Responses

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Abstract

Evidence accumulated over 30 years, from experiments on animals and human subjects, has conclusively demonstrated that inputs from the vestibular otolith organs contribute to the control of blood pressure during movement and changes in posture. This review considers the effects of gravity on the body axis, and the consequences of postural changes on blood distribution in the body. It then separately considers findings collected in experiments on animals and human subjects demonstrating that the vestibular system regulates blood distribution in the body during movement. Vestibulosympathetic reflexes differ from responses triggered by unloading of cardiovascular receptors such as baroreceptors and cardiopulmonary receptors, as they can be elicited before a change in blood distribution occurs in the body. Dissimilarities in the expression of vestibulosympathetic reflexes in humans and animals are also described. In particular, there is evidence from experiments in animals, but not humans, that vestibulosympathetic reflexes are patterned, and differ between body regions. Results from neurophysiological and neuroanatomical studies in animals are discussed that identify the neurons that mediate vestibulosympathetic responses, which include cells in the caudal aspect of the vestibular nucleus complex, interneurons in the lateral medullary reticular formation, and bulbospinal neurons in the rostral ventrolateral medulla. Recent findings showing that cognition can modify the gain of vestibulosympathetic responses are also presented, and neural pathways that could mediate adaptive plasticity in the responses are proposed, including connections of the posterior cerebellar vermis with the vestibular nuclei and brainstem nuclei that regulate blood pressure. © 2014 American Physiological Society. Compr Physiol 4:851‐887, 2014.

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Figure 1. Figure 1. Primary connections of the sympathetic and parasympathetic nervous system that control blood flow and blood pressure. Parasympathetic preganglionic neurons (PrG) whose cell bodies are located in the brainstem send axons principally through the vagus nerve to postganglionic neurons (PoG) whose cell bodies are located in ganglia near the heart. Parasympathetic PrG release the neurotransmitter acetylcholine (Ach) onto nicotinic (N) receptors on the cell body and dendrites of parasympathetic PoG. Parasympathetic PoG release acetylcholine onto muscarinic receptors on the surface of autorhythmic (pacemaker) cells in the heart, particularly those in the sinoatrial node. The binding of acetylcholine to these muscarinic receptors induces a decrease in heart rate. Sympathetic PrG whose cell bodies are located in the thoracic and lumbar spinal cord send axons to PoG whose cell bodies are located in prevertebral or paravertebral ganglia. Like parasympathetic PrG, sympathetic PrG release Ach onto nicotinic receptors located on the cell body and dendrites of sympathetic PoG. Sympathetic PoG project to the heart, and release the neurotransmitter norepinephrine (NE) onto β1‐receptors located on the surface of pacemaker cells. The binding of norepinephrine to these receptors induces an increase in heart rate. Sympathetic PoG additionally release norepinephrine onto β1‐receptors located on myocytes in the ventricles of the heart. Binding of neurotransmitter to these receptors induces an increase in contractility of the muscle cells. Furthermore, sympathetic PoG innervate smooth muscle in the walls of blood vessels, primarily arterioles. Norepinephrine released from PoG binds primarily to α‐receptors on the surface of vascular smooth muscle. Binding of norepinephrine to these receptors causes vasoconstriction, and results in decreased blood flow through the affected vessels. In addition, sympathetic PrG release acetylcholine onto nicotinic receptors on adrenal chromaffin cells. Binding of acetylcholine to these receptors induces the release of epinephrine (E) and some norepinephrine from the chromaffin cells. Epinephrine preferentially binds to β‐receptors, and elicits an increase in heart rate and ventricular contractility by binding to β1‐receptors in the heart. Epinephrine also binds to β2‐receptors associated with vascular smooth muscle in particular vascular beds, including arterioles in skeletal muscle. Binding of epinephrine to β2‐receptors results in vasodilation. However, when epinephrine levels are high, the hormone binds to α‐receptors and causes vasoconstriction. Thus, epinephrine can result in an increase or decrease in blood flow to a particular tissue, depending on the amount of the hormone released into the bloodstream.
Figure 2. Figure 2. Pressures (mmHg) in the large arteries (red) and veins (blue) when lying supine or standing.
Figure 3. Figure 3. Average changes in femoral artery (top panel) and vein (middle panel) blood flow during 20°, 40°, and 60° head‐up tilts. Bottom trace: instantaneous blood accumulation at each time period, determined by subtraction of percent difference from baseline in venous blood flow from percent difference from baseline in arterial blood flow. Symbols designate changes in blood flow and blood accumulation elicited by 40° and 60° tilt that were significantly different from those resulting from 20° tilt (ANOVA test). Adapted from (331), with permission.
Figure 4. Figure 4. Section through the head showing the middle and inner ear. The portion of the inner ear containing the vestibular system endorgans is shaded in yellow.
Figure 5. Figure 5. Effect of increasing mean blood pressure (BP) by injecting an alpha adrenergic agonist on averaged superior mesenteric nerve responses elicited by a train of electrical stimuli delivered to vestibular afferents. Arrows indicate the latency of the stimulus. When blood pressure was normal (98 mmHg, top), stimulation of the vestibular nerve elicited large changes in sympathetic nerve activity. However, when blood pressure was raised modestly (132 mmHg, bottom), the responses were attenuated. Vertical calibration, 1 μV; time scale, 100 ms. Adapted from (170), with permission.
Figure 6. Figure 6. Effects of electrical vestibular stimulation (indicated by a bar at the bottom of traces) on arterial blood pressure (top trace) and brachial artery (middle trace) and femoral artery (bottom trace) blood flow. Adapted from (168), with permission.
Figure 7. Figure 7. (A) Averaged splanchnic nerve responses to 15° head rotations in vertical planes. The rotations were delivered at 0.2 Hz; in the left diagram the head was rotated in the clockwise direction, and in the right diagram the head rotations were in the counterclockwise direction. During both stimuli, maximal nerve activity occurred during nose‐up head rotations. (B) Polar diagram of vestibular vector orientations for splanchnic nerve responses to vestibular stimulation. The position of a symbol indicates the direction of tilt that produced maximal sympathetic nerve activity. Abbreviations: CED, contralateral ear down tilt; IED, ipsilateral ear down tilt; ND, nose down tilt; NU, nose up tilt. Adapted from (327), with permission.
Figure 8. Figure 8. Bode diagrams of responses of the splanchnic nerve to head rotations. The responses whose characteristics are depicted were elicited by performing sinusoidal head rotations in the best plane for producing a response. Different symbols are used to designate responses from each animal. Responses gains were standardized by dividing the gain at each frequency by the average gain across frequencies. Data are plotted with respect to stimulus position. Adapted from (327), with permission.
Figure 9. Figure 9. The average effects of removal of vestibular inputs on femoral artery (hindlimb; left column) and brachial artery (forelimb; right column) blood flow and vascular resistance during 60° head‐up tilts. Blue lines depict average changes in blood flow and vascular resistance prior to vestibular lesions; red lines and green lines respectively show tilt‐related changes in blood flow and vascular resistance during the first week and subsequent 3 weeks after removal of vestibular inputs. Symbols designate postlesion changes in blood flow and vascular resistance during tilts that were significantly different from those recorded when vestibular inputs were present. Error bars indicate S.E.M. Adapted from (307), with permission.
Figure 10. Figure 10. Neural regions that generate and modify the gains of vestibulosympathetic reflexes (VSR) and baroreceptor reflexes. Abbreviations: BA, baroreceptor afferent; BP, blood pressure; IML, intermediolateral cell column; IO, inferior olivary nucleus; IX, cerebellar lobule IX, uvula; NTS, nucleus tractus solitaries; PBN, parabrachial nucleus; RF, reticular formation; RVLM: rostral ventrolateral medulla; VA, vestibular afferent; VN, vestibular nucleus complex.
Figure 11. Figure 11. Cardiac‐locked muscle sympathetic bursts are modulated by dynamic vestibular inputs. Experimental records from one subject. Spontaneous muscle sympathetic nerve activity was recorded from the peronei motor fascicle of the common peroneal nerve, and is presented as the filtered neurogram (nerve) and as an RMS‐processed signal (RMS nerve). In each panel, the top trace indicates the onset and phase of the sinusoidal modulation when applied (B‐D) and the bottom trace records the ECG. Each panel spans a 4 s data period. (A) Baseline activity and (B‐D) consecutive sequences obtained during sinusoidal galvanic vestibular stimulation (GVS) at 0.5 Hz. The rectangles illustrate the relationship between the sympathetic burst and the cardiac rhythm (c) and the vestibular rhythm (v). Reproduced from (29), with permission.
Figure 12. Figure 12. Correlations between muscle sympathetic bursts and cardiac and vestibular rhythms. (A) Cross‐correlation histograms of the relationship between muscle sympathetic nerve activity (MSNA) and the electrocardiogram (ECG; white histogram) and autocorrelogram of the ECG (black histogram). (B and C) Cross‐correlation histograms between ECG and galvanic vestibular stimulation (GVS) and respiration (inspiratory peaks) and GVS. A 0.5 Hz sine wave has been superimposed on the histogram to illustrate the timing of the GVS; it has been inverted for clarity. (D and E) Cross‐correlation histograms of MSNA with respect to the vestibular input (GVS), in white, or to a control sine wave (control), in black. Data in panels A‐D are from the same subject represented in Figure 11; data in panel E were obtained from another subject. 20 ms bins in all panels. n = the numbers of counts comprising the histograms. Reproduced from (29), with permission.
Figure 13. Figure 13. Variation in relative contributions of cardiac and vestibular rhythms over time. Cross‐correlation histograms of the relationship between muscle sympathetic nerve activity (MSNA) and galvanic vestibular stimulation (GVS; white histogram) and the electrocardiogram (ECG, black histogram) after dividing the data into four consecutive 30 s segments, each composed of 15 cycles of GVS (0.5 Hz). The relative influences of the cardiac and vestibular rhythms changed during the course of stimulation. The muscle sympathetic nerve activity (MSNA)—ECG cross‐correlograms have been compressed vertically to better illustrate these temporal relationships: 100 spikes is represented by one division on the vertical scale for these data. 20 ms bins in all panels. n = the numbers of counts comprising the histograms. Same subject as in Figure 11 and Figure 12A‐C. Reproduced from (29), with permission.
Figure 14. Figure 14. Cross‐correlation histograms between muscle sympathetic nerve activity (MSNA) and sinusoidal galvanic vestibular stimulation (sGVS) in one subject. The thick curve superimposed on the histograms is the smoothed polynomial that was fitted to the data. The sinusoid above represents the galvanic stimulus, delivered at 0.08, 0.13, and 0.18 Hz. Each cross‐correlation histogram shows a large peak of modulation (primary peak), associated with the positive peak of the sinusoid, and a smaller peak (secondary peak). The secondary peak was largest at 0.08 Hz and smallest at 0.18 Hz. Reproduced from (133), with permission.
Figure 15. Figure 15. Bilateral recordings of muscle sympathetic nerve activity, together with ECG, blood pressure and respiration, during sinusoidal galvanic vestibular stimulation (GVS) at 0.08 Hz in one subject. Overall, sympathetic outflow was similar between the two sides, but close inspection revealed subtle differences. In the expanded sections, the sympathetic bursts have been shifted back 1.25 s in time to account for peripheral conduction delays, allowing those bursts aligned with the cardiac cycle (“c”) or vestibular stimulus (“v”) to be identified. Reproduced from (93), with permission.
Figure 16. Figure 16. Modulation indices of primary peak of skin sympathetic nerve activity (SSNA) during sinusoidal galvanic vestibular stimulation (sGVS) at different frequencies as a function of whether or not subjects reported nausea. It is evident that modulation indices were higher in those subjects who reported nausea. Reproduced from (132), with permission.
Figure 17. Figure 17. Mean and 95% confidence interval of mean of low frequency/high frequency (LF/HF ratio of heart rate variability during active change in posture, as follows: 5 min supine rest, 5 min back‐unsupported sitting, and 5 min upright stance. Data from seven persons with unilateral vestibular failure and seven healthy age/sex matched volunteers at (A) day 1 and (B) week 2. Adapted from (158); used with permission.
Figure 18. Figure 18. Head‐down neck flexion posture first used by Essandoh et al. (95). (A) The subject is prone, with neck slightly extended and the chin resting comfortably on a soft‐padded support at the edge of the table. This represents the head‐up posture (B) chin support is removed, and subject's head is lowered to maximally flex the neck. This represents the head‐down neck flexion (HDNF) posture.
Figure 19. Figure 19. Recordings of muscle and skin sympathetic nerve activity in two subjects, during baseline and head‐down neck flexion (HDNF) conditions. Muscle sympathetic nerve activity was increased during HDNF, whereas skin sympathetic nerve activity was unchanged during HDNF. From (239); used with permission.
Figure 20. Figure 20. Hemodynamic, respiratory, and autonomic modulations during off‐vertical axis rotation (OVAR) at 60°/s. (A) Phase of respiratory cycle; (B) RR interval; (C) diastolic blood pressure; (D) change in MSNA; (E) changes in the naso‐occipital and interaural components of the gravity vector over each cycle of OVAR. Inserts on top indicate the direction of rotation and the position of the head at various phases of the OVAR cycle. Data are the means ± SE from 10 consecutive cycles of rotation in seven subjects (LSD, left side down; NU, nose‐up; RSD, right side down; ND, nose down). Adapted from (167); used with permission.
Figure 21. Figure 21. Muscle sympathetic nerve activity (MSNA) during earth vertical axis rotation (EVAR) at 60°/s (A) and off‐vertical axis rotation (OVAR) at 24°/s (B) 60°/s (C) and 110°/s (D). The axis of rotation was tilted 15° during OVAR, resulting in a peak acceleration of 0.26 g along the interaural axis. Upper tracings, MSNA; lower tracings, signal from the chair holding the subject. The vertical breaks indicate 360° of rotation and, in B‐D, the nose‐up position. Inserts over the vertical breaks show the nose‐up position of the subject and the axis or rotation. Calibrations are for MSNA voltage and time. From (167); used with permission.


Figure 1. Primary connections of the sympathetic and parasympathetic nervous system that control blood flow and blood pressure. Parasympathetic preganglionic neurons (PrG) whose cell bodies are located in the brainstem send axons principally through the vagus nerve to postganglionic neurons (PoG) whose cell bodies are located in ganglia near the heart. Parasympathetic PrG release the neurotransmitter acetylcholine (Ach) onto nicotinic (N) receptors on the cell body and dendrites of parasympathetic PoG. Parasympathetic PoG release acetylcholine onto muscarinic receptors on the surface of autorhythmic (pacemaker) cells in the heart, particularly those in the sinoatrial node. The binding of acetylcholine to these muscarinic receptors induces a decrease in heart rate. Sympathetic PrG whose cell bodies are located in the thoracic and lumbar spinal cord send axons to PoG whose cell bodies are located in prevertebral or paravertebral ganglia. Like parasympathetic PrG, sympathetic PrG release Ach onto nicotinic receptors located on the cell body and dendrites of sympathetic PoG. Sympathetic PoG project to the heart, and release the neurotransmitter norepinephrine (NE) onto β1‐receptors located on the surface of pacemaker cells. The binding of norepinephrine to these receptors induces an increase in heart rate. Sympathetic PoG additionally release norepinephrine onto β1‐receptors located on myocytes in the ventricles of the heart. Binding of neurotransmitter to these receptors induces an increase in contractility of the muscle cells. Furthermore, sympathetic PoG innervate smooth muscle in the walls of blood vessels, primarily arterioles. Norepinephrine released from PoG binds primarily to α‐receptors on the surface of vascular smooth muscle. Binding of norepinephrine to these receptors causes vasoconstriction, and results in decreased blood flow through the affected vessels. In addition, sympathetic PrG release acetylcholine onto nicotinic receptors on adrenal chromaffin cells. Binding of acetylcholine to these receptors induces the release of epinephrine (E) and some norepinephrine from the chromaffin cells. Epinephrine preferentially binds to β‐receptors, and elicits an increase in heart rate and ventricular contractility by binding to β1‐receptors in the heart. Epinephrine also binds to β2‐receptors associated with vascular smooth muscle in particular vascular beds, including arterioles in skeletal muscle. Binding of epinephrine to β2‐receptors results in vasodilation. However, when epinephrine levels are high, the hormone binds to α‐receptors and causes vasoconstriction. Thus, epinephrine can result in an increase or decrease in blood flow to a particular tissue, depending on the amount of the hormone released into the bloodstream.


Figure 2. Pressures (mmHg) in the large arteries (red) and veins (blue) when lying supine or standing.


Figure 3. Average changes in femoral artery (top panel) and vein (middle panel) blood flow during 20°, 40°, and 60° head‐up tilts. Bottom trace: instantaneous blood accumulation at each time period, determined by subtraction of percent difference from baseline in venous blood flow from percent difference from baseline in arterial blood flow. Symbols designate changes in blood flow and blood accumulation elicited by 40° and 60° tilt that were significantly different from those resulting from 20° tilt (ANOVA test). Adapted from (331), with permission.


Figure 4. Section through the head showing the middle and inner ear. The portion of the inner ear containing the vestibular system endorgans is shaded in yellow.


Figure 5. Effect of increasing mean blood pressure (BP) by injecting an alpha adrenergic agonist on averaged superior mesenteric nerve responses elicited by a train of electrical stimuli delivered to vestibular afferents. Arrows indicate the latency of the stimulus. When blood pressure was normal (98 mmHg, top), stimulation of the vestibular nerve elicited large changes in sympathetic nerve activity. However, when blood pressure was raised modestly (132 mmHg, bottom), the responses were attenuated. Vertical calibration, 1 μV; time scale, 100 ms. Adapted from (170), with permission.


Figure 6. Effects of electrical vestibular stimulation (indicated by a bar at the bottom of traces) on arterial blood pressure (top trace) and brachial artery (middle trace) and femoral artery (bottom trace) blood flow. Adapted from (168), with permission.


Figure 7. (A) Averaged splanchnic nerve responses to 15° head rotations in vertical planes. The rotations were delivered at 0.2 Hz; in the left diagram the head was rotated in the clockwise direction, and in the right diagram the head rotations were in the counterclockwise direction. During both stimuli, maximal nerve activity occurred during nose‐up head rotations. (B) Polar diagram of vestibular vector orientations for splanchnic nerve responses to vestibular stimulation. The position of a symbol indicates the direction of tilt that produced maximal sympathetic nerve activity. Abbreviations: CED, contralateral ear down tilt; IED, ipsilateral ear down tilt; ND, nose down tilt; NU, nose up tilt. Adapted from (327), with permission.


Figure 8. Bode diagrams of responses of the splanchnic nerve to head rotations. The responses whose characteristics are depicted were elicited by performing sinusoidal head rotations in the best plane for producing a response. Different symbols are used to designate responses from each animal. Responses gains were standardized by dividing the gain at each frequency by the average gain across frequencies. Data are plotted with respect to stimulus position. Adapted from (327), with permission.


Figure 9. The average effects of removal of vestibular inputs on femoral artery (hindlimb; left column) and brachial artery (forelimb; right column) blood flow and vascular resistance during 60° head‐up tilts. Blue lines depict average changes in blood flow and vascular resistance prior to vestibular lesions; red lines and green lines respectively show tilt‐related changes in blood flow and vascular resistance during the first week and subsequent 3 weeks after removal of vestibular inputs. Symbols designate postlesion changes in blood flow and vascular resistance during tilts that were significantly different from those recorded when vestibular inputs were present. Error bars indicate S.E.M. Adapted from (307), with permission.


Figure 10. Neural regions that generate and modify the gains of vestibulosympathetic reflexes (VSR) and baroreceptor reflexes. Abbreviations: BA, baroreceptor afferent; BP, blood pressure; IML, intermediolateral cell column; IO, inferior olivary nucleus; IX, cerebellar lobule IX, uvula; NTS, nucleus tractus solitaries; PBN, parabrachial nucleus; RF, reticular formation; RVLM: rostral ventrolateral medulla; VA, vestibular afferent; VN, vestibular nucleus complex.


Figure 11. Cardiac‐locked muscle sympathetic bursts are modulated by dynamic vestibular inputs. Experimental records from one subject. Spontaneous muscle sympathetic nerve activity was recorded from the peronei motor fascicle of the common peroneal nerve, and is presented as the filtered neurogram (nerve) and as an RMS‐processed signal (RMS nerve). In each panel, the top trace indicates the onset and phase of the sinusoidal modulation when applied (B‐D) and the bottom trace records the ECG. Each panel spans a 4 s data period. (A) Baseline activity and (B‐D) consecutive sequences obtained during sinusoidal galvanic vestibular stimulation (GVS) at 0.5 Hz. The rectangles illustrate the relationship between the sympathetic burst and the cardiac rhythm (c) and the vestibular rhythm (v). Reproduced from (29), with permission.


Figure 12. Correlations between muscle sympathetic bursts and cardiac and vestibular rhythms. (A) Cross‐correlation histograms of the relationship between muscle sympathetic nerve activity (MSNA) and the electrocardiogram (ECG; white histogram) and autocorrelogram of the ECG (black histogram). (B and C) Cross‐correlation histograms between ECG and galvanic vestibular stimulation (GVS) and respiration (inspiratory peaks) and GVS. A 0.5 Hz sine wave has been superimposed on the histogram to illustrate the timing of the GVS; it has been inverted for clarity. (D and E) Cross‐correlation histograms of MSNA with respect to the vestibular input (GVS), in white, or to a control sine wave (control), in black. Data in panels A‐D are from the same subject represented in Figure 11; data in panel E were obtained from another subject. 20 ms bins in all panels. n = the numbers of counts comprising the histograms. Reproduced from (29), with permission.


Figure 13. Variation in relative contributions of cardiac and vestibular rhythms over time. Cross‐correlation histograms of the relationship between muscle sympathetic nerve activity (MSNA) and galvanic vestibular stimulation (GVS; white histogram) and the electrocardiogram (ECG, black histogram) after dividing the data into four consecutive 30 s segments, each composed of 15 cycles of GVS (0.5 Hz). The relative influences of the cardiac and vestibular rhythms changed during the course of stimulation. The muscle sympathetic nerve activity (MSNA)—ECG cross‐correlograms have been compressed vertically to better illustrate these temporal relationships: 100 spikes is represented by one division on the vertical scale for these data. 20 ms bins in all panels. n = the numbers of counts comprising the histograms. Same subject as in Figure 11 and Figure 12A‐C. Reproduced from (29), with permission.


Figure 14. Cross‐correlation histograms between muscle sympathetic nerve activity (MSNA) and sinusoidal galvanic vestibular stimulation (sGVS) in one subject. The thick curve superimposed on the histograms is the smoothed polynomial that was fitted to the data. The sinusoid above represents the galvanic stimulus, delivered at 0.08, 0.13, and 0.18 Hz. Each cross‐correlation histogram shows a large peak of modulation (primary peak), associated with the positive peak of the sinusoid, and a smaller peak (secondary peak). The secondary peak was largest at 0.08 Hz and smallest at 0.18 Hz. Reproduced from (133), with permission.


Figure 15. Bilateral recordings of muscle sympathetic nerve activity, together with ECG, blood pressure and respiration, during sinusoidal galvanic vestibular stimulation (GVS) at 0.08 Hz in one subject. Overall, sympathetic outflow was similar between the two sides, but close inspection revealed subtle differences. In the expanded sections, the sympathetic bursts have been shifted back 1.25 s in time to account for peripheral conduction delays, allowing those bursts aligned with the cardiac cycle (“c”) or vestibular stimulus (“v”) to be identified. Reproduced from (93), with permission.


Figure 16. Modulation indices of primary peak of skin sympathetic nerve activity (SSNA) during sinusoidal galvanic vestibular stimulation (sGVS) at different frequencies as a function of whether or not subjects reported nausea. It is evident that modulation indices were higher in those subjects who reported nausea. Reproduced from (132), with permission.


Figure 17. Mean and 95% confidence interval of mean of low frequency/high frequency (LF/HF ratio of heart rate variability during active change in posture, as follows: 5 min supine rest, 5 min back‐unsupported sitting, and 5 min upright stance. Data from seven persons with unilateral vestibular failure and seven healthy age/sex matched volunteers at (A) day 1 and (B) week 2. Adapted from (158); used with permission.


Figure 18. Head‐down neck flexion posture first used by Essandoh et al. (95). (A) The subject is prone, with neck slightly extended and the chin resting comfortably on a soft‐padded support at the edge of the table. This represents the head‐up posture (B) chin support is removed, and subject's head is lowered to maximally flex the neck. This represents the head‐down neck flexion (HDNF) posture.


Figure 19. Recordings of muscle and skin sympathetic nerve activity in two subjects, during baseline and head‐down neck flexion (HDNF) conditions. Muscle sympathetic nerve activity was increased during HDNF, whereas skin sympathetic nerve activity was unchanged during HDNF. From (239); used with permission.


Figure 20. Hemodynamic, respiratory, and autonomic modulations during off‐vertical axis rotation (OVAR) at 60°/s. (A) Phase of respiratory cycle; (B) RR interval; (C) diastolic blood pressure; (D) change in MSNA; (E) changes in the naso‐occipital and interaural components of the gravity vector over each cycle of OVAR. Inserts on top indicate the direction of rotation and the position of the head at various phases of the OVAR cycle. Data are the means ± SE from 10 consecutive cycles of rotation in seven subjects (LSD, left side down; NU, nose‐up; RSD, right side down; ND, nose down). Adapted from (167); used with permission.


Figure 21. Muscle sympathetic nerve activity (MSNA) during earth vertical axis rotation (EVAR) at 60°/s (A) and off‐vertical axis rotation (OVAR) at 24°/s (B) 60°/s (C) and 110°/s (D). The axis of rotation was tilted 15° during OVAR, resulting in a peak acceleration of 0.26 g along the interaural axis. Upper tracings, MSNA; lower tracings, signal from the chair holding the subject. The vertical breaks indicate 360° of rotation and, in B‐D, the nose‐up position. Inserts over the vertical breaks show the nose‐up position of the subject and the axis or rotation. Calibrations are for MSNA voltage and time. From (167); used with permission.
References
 1. Abboud FM , Thames MD . Interaction of cardiovascular reflexes in circulatory control. In: Shepherd JT , Abboud FM , editors. Handbook of Physiology Section 2: Circulation Volume III: Peripheral Circulation and Organ Blood Flow, Part 2. Bethesa, MD: American Physiological Society, 1983, pp. 497‐555.
 2. Abe C , Kawada T , Sugimachi M , Morita H . Interaction between vestibulo‐cardiovascular reflex and arterial baroreflex during postural change in rats. J Appl Physiol 111: 1614‐1621, 2011.
 3. Abe C , Tanaka K , Awazu C , Chen H , Morita H . Plastic alteration of vestibulo‐cardiovascular reflex induced by 2 weeks of 3‐G load in conscious rats. Exp Brain Res 181: 639‐646, 2007.
 4. Abe C , Tanaka K , Awazu C , Morita H . Strong galvanic vestibular stimulation obscures arterial pressure response to gravitational change in conscious rats. J Appl Physiol 104: 34‐40, 2008.
 5. Abe C , Tanaka K , Awazu C , Morita H . The vestibular system is integral in regulating plastic alterations in the pressor response to free drop mediated by the nonvestibular system. Neurosci Lett 445: 149‐152, 2008.
 6. Agarwal SK , Calaresu FR . Supramedullary inputs to cardiovascular neurons of rostral ventrolateral medulla in rats. Am J Physiol 265: R111‐R116, 1993.
 7. Anderson JH , Blanks RHI , Precht W . Response characteristics of semicircular canal and otolith systems in the cat. I. Dynamic responses of primary vestibular fibers. Exp Brain Res 32: 491‐507, 1978.
 8. Andrezik JA , Dormer KJ , Foreman RD , Person RJ . Fastigial nucleus projections to the brain stem in beagles: Pathways for autonomic regulation. Neurosci 11: 497‐507, 1984.
 9. Angaut P , Brodal A . The projection of the “vestibulocerebellum” onto the vestibular nuclei in the cat. Arch Ital Biol 105: 441‐479, 1967.
 10. Aoki M , Sakaida Y , Hayashi H , Yamada N , Mizuta K , Ito Y . The orthostatic dysregulation of blood pressure in dizzy patients. J Vestib Res 18: 223‐229, 2008.
 11. Aoki M , Sakaida Y , Tanaka K , Mizuta K , Ito Y . Evidence for vestibular dysfunction in orthostatic hypotension. Exp Brain Res 217: 251‐259, 2012.
 12. Arndt JO , Brambring P , Hindorf K , Rohnelt M . The afferent discharge pattern of atrial mechanoreceptors in the cat during sinusoidal stretch of atrial strips in situ. J Physiol 240: 33‐52, 1974.
 13. Arshian MS , Puterbaugh SR , Miller DJ , Catanzaro MF , Hobson CE , McCall AA , Yates BJ . Effects of visceral inputs on the processing of labyrinthine signals by the inferior and caudal medial vestibular nuclei: Ramifications for the production of motion sickness. Exp Brain Res 228: 353‐363, 2013.
 14. Bahr R , Bartel B , Blumberg H , Janig W . Functional characterization of preganglionic neurons projecting in the lumbar splanchnic nerves: Vasoconstrictor neurons. J Auton Nerv Syst 15: 131‐140, 1986.
 15. Bahr R , Blumberg H , Janig W . Do dichotomizing afferent fibers exist which supply visceral organs as well as somatic structures? A contribution to the problem or referred pain. Neurosci Lett 24: 25‐28, 1981.
 16. Balaban CD . Neural substrates linking balance control and anxiety. Physiol Behav 77: 469‐475, 2002.
 17. Balaban CD , Beryozkin G . Vestibular nucleus projections to nucleus tractus solitarius and the dorsal motor nucleus of the vagus nerve: Potential substrates for vestibulo‐autonomic interactions. Exp Brain Res 98: 200‐212, 1994.
 18. Balaban CD , Jacob RG . Background and history of the interface between anxiety and vertigo. J Anxiety Disord 15: 27‐51, 2001.
 19. Balaban CD , Jacob RG , Furman JM . Neurologic bases for comorbidity of balance disorders, anxiety disorders and migraine: Neurotherapeutic implications. Expert Rev Neurother 11: 379‐394, 2011.
 20. Balaban CD , Porter JD . Neuroanatomic substrates for vestibulo‐autonomic interactions. J Vestib Res 8: 7‐16, 1998.
 21. Balaban CD , Thayer JF . Neurological bases for balance‐anxiety links. J Anxiety Disord 15: 53‐79, 2001.
 22. Balaban CD , Yates BJ . Vestibulo‐autonomic interactions: A teleologic perspective. In: Highstein SM , Fay RR , Popper AN , editors. Anatomy and Physiology of the Central and Peripheral Vestibular System. Heidelberg: Springer, 2004, pp. 286‐342.
 23. Barmack NH . Central vestibular system: Vestibular nuclei and posterior cerebellum. Brain Res Bull 60: 511‐541, 2003.
 24. Barman SM , Gebber GL . Rostral ventrolateral medullary and caudal medullary raphe neurons with activity correlated to the 10‐Hz rhythm in sympathetic nerve discharge. J Neurophysiol 68: 1535‐1547, 1992.
 25. Barman SM , Gebber GL . The posterior vermis of the cerebellum selectively inhibits 10‐Hz sympathetic nerve discharge in anesthetized cats. Am J Physiol Reg Integr Comp Physiol 297: R210‐217, 2009.
 26. Barman SM , Gebber GL , Calaresu FR . Differential control of sympathetic nerve discharge by the brain stem. Am J Physiol 247: R513‐519, 1984.
 27. Barman SM , Sugiyama Y , Suzuki T , Cotter LA , DeStefino VJ , Reighard DA , Cass SP , Yates BJ . Rhythmic activity of neurons in the rostral ventrolateral medulla of conscious cats: Effect of removal of vestibular inputs. Am J Physiol Regul Integr Comp Physiol 301: R937‐946, 2011.
 28. Beart PM , Summers RJ , Stephenson JA , Christie MJ . Excitatory amino acid projections to the nucleus of the solitary tract in the rat: A retrograde transport study utilizing D‐[3H]aspartate and [3H]GABA. J Auton Nerv Syst 50: 109‐122, 1994.
 29. Bent LR , Bolton PS , Macefield VG . Modulation of muscle sympathetic bursts by sinusoidal galvanic vestibular stimulation in human subjects. Exp Brain Res 174: 701‐711, 2006.
 30. Bent LR , Bolton PS , Macefield VG . Vestibular inputs do not influence the fusimotor system in relaxed muscles of the human leg. Exp Brain Res 180: 97‐103, 2007.
 31. Bent LR , Sander M , Bolton PS , Macefield VG . The vestibular system does not modulate fusimotor drive to muscle spindles in contracting leg muscles of seated subjects. Exp Brain Res 227: 175‐183, 2013.
 32. Berdeaux A , Duranteau J , Pussard E , Edouard A , Giudicelli JF . Baroreflex control of regional vascular resistances during simulated orthostatism. Kidney Int Suppl 37: S29‐33, 1992.
 33. Bishop VS , Malliani A , Thoren P . Cardiac mechanoreceptors. In: Shepherd JT , Abboud FM , editors. Handbook of Physiology Section 2: Circulation Volume III: Peripheral Circulation and Organ Blood Flow, Part 2, edited by . Bethesa, MD: American Physiological Society, 1983, pp. 497‐555.
 34. Bles W , Bos JE , Kruit H . Motion sickness. Curr Opin Neurol 13: 19‐25, 2000.
 35. Blomqvist C , Stone H . Cardiovascular adjustments to gravitational stress. In: Shepherd JT , Abboud FM , editors. Handbook of Physiology The Cardiovascular System Sect 2, Vol. III. . Bethesda: American Physiological Society, 1983, pp. 1025‐1063.
 36. Boczek‐Funcke A , Dembowsky K , Häbler H‐J , Jänig W , McAllen RM , Michaelis M . Classification of preganglionic neurones projecting into the cat cervical sympathetic trunk. J Physiol 453: 319‐339, 1992.
 37. Bolton PS , Kerman IA , Woodring SF , Yates BJ . Influences of neck afferents on sympathetic and respiratory nerve activity. Brain Res Bull 47: 413‐419, 1998.
 38. Bolton PS , Wardman DL , Macefield VG . Absence of short‐term vestibular modulation of muscle sympathetic outflow, assessed by brief galvanic vestibular stimulation in awake human subjects. Exp Brain Res 154: 39‐43, 2004.
 39. Bourassa EA , Sved AF , Speth RC . Angiotensin modulation of rostral ventrolateral medulla (RVLM) in cardiovascular regulation. Mol Cell Endocrinol 302: 167‐175, 2009.
 40. Boyle R , Pompeiano O . Convergence and interaction of neck and macular vestibular inputs on vestibulospinal neurons. J Neurophysiol 45: 852‐868, 1981.
 41. Bradley DJ , Ghelarducci B , La Noce A , Paton JF , Spyer KM , Withington‐Wray DJ . An electrophysiological and anatomical study of afferents reaching the cerebellar uvula in the rabbit. Exp Physiol 75: 163‐177, 1990.
 42. Bradley DJ , Ghelarducci B , Paton JF , Spyer KM . The cardiovascular responses elicited from the posterior cerebellar cortex in the anaesthetized and decerebrate rabbit. J Physiol 383: 537‐550, 1987.
 43. Bradley DJ , Ghelarducci B , Spyer KM . The role of the posterior cerebellar vermis in cardiovascular control. Neurosci Res 12: 45‐56, 1991.
 44. Bradley DJ , Pascoe JP , Paton JF , Spyer KM . Cardiovascular and respiratory responses evoked from the posterior cerebellar cortex and fastigial nucleus in the cat. J Physiol 393: 107‐121, 1987.
 45. Bradley DJ , Paton JF , Spyer KM . Cardiovascular responses evoked from the fastigial region of the cerebellum in anaesthetized and decerebrate rabbits. J Physiol 392: 475‐491, 1987.
 46. Brodal A . The olivocerebellar projection in the cat as studied with the method of retrograde axonal transport of horseradish peroxidase. II. The projection to the uvula. J Comp Neurol 166: 417‐426, 1976.
 47. Brooks JX , Cullen KE . Multimodal integration in rostral fastigial nucleus provides an estimate of body movement. J Neurosci 29: 10499‐10511, 2009.
 48. Broussard DM , Titley HK , Antflick J , Hampson DR . Motor learning in the VOR: The cerebellar component. Exp Brain Res 210: 451‐463, 2011.
 49. Burke DS , Sundölf G , Wallin BG . Postural effects on muscle nerve sympathetic activity in man. J Physiol 272: 399‐414, 1977.
 50. Buttner U , Glasauer S , Glonti L , Kleine JF , Siebold C . Otolith processing in the deep cerebellar nuclei. Ann N Y Acad Sci 871: 81‐93, 1999.
 51. Cai YL , Ma WL , Li M , Guo JS , Li YQ , Wang LG , Wang WZ . Glutamatergic vestibular neurons express Fos after vestibular stimulation and project to the NTS and the PBN in rats. Neurosci Lett 417: 132‐137, 2007.
 52. Cannon WB . Bodily Changes in Pain, Hunger, Fear and Rage: An Account of Recent Researches into the Function of Emotional Excitement. New York: Harper & Row, 1963.
 53. Cannon WB. The Wisdom of the Body. New York: W. W. Norton, 1963.
 54. Cano G , Card JP , Sved AF . Dual viral transneuronal tracing of central autonomic circuits involved in the innervation of the two kidneys in rat. J Comp Neurol 471: 462‐481, 2004.
 55. Carleton SC , Carpenter MB . Afferent and efferent connections of the medial, inferior and lateral vestibular nuclei in the cat and monkey. Brain Res 278: 29‐51, 1983.
 56. Carli G , Diete‐Spiff K , Pompeiano O . Responses of the muscle spindles and of the extrafusal fibres in an externsor muscle to stimulation of the lateral vestibular nucleus in the cat. Arch Ital Biol 105: 209‐242, 1967.
 57. Carlino L , Weber SA , Gowen MF , Yates BJ . Selective innervation of upper and loer thoracic spinal segments by medullary raphe neurons. FASEB J 26: 1091.2, 2012.
 58. Carpenter MB , Bard DS , Alling FA . Anatomical connections between the fastigial nuclei, the labyrinth and the vestibular nuclei in the cat. J Comp Neurol 111: 1‐26, 1959.
 59. Carter JR , Kupiers NT , Ray CA . Neurovascular responses to mental stress. J Physiol 564: 321‐327, 2005.
 60. Cathers I , Day BL , Fitzpatrick RC . Otolith and canal reflexes in human standing. J Physiol 563: 229‐234, 2005.
 61. Chalmers J , Arnolda L , Llewellynsmith I , Minson J , Pilowsky P , Suzuki S . Central neurons and neurotransmitters in the control of blood pressure. Clin Exp Pharmacol Physiol 21: 819‐829, 1994.
 62. Cobbold AF , Megirian D , Sherrey JH . Vestibular evoked activity in autonomic motor outflows. Arch Ital Biol 106: 113‐123, 1968.
 63. Cohen B , Martinelli GP , Raphan T , Schaffner A , Xiang Y , Holstein GR , Yakushin SB . The vasovagal response of the rat: Its relation to the vestibulosympathetic reflex and to Mayer waves. FASEB J 27: 2564‐2572, 2013.
 64. Cohen MI , Gootman PM . Periodicities in efferent discharge of splanchnic nerve of the cat. Am J Physiol 218: 1092‐1101, 1970.
 65. Colebatch J , Halmagyi G . Vestibular evoked potentials in human neck muscles before and after unilateral vestibular deafferentation. Neurology 42: 1635‐1636, 1992.
 66. Colebatch J , Halmagyi G , Skuse N . Myogenic potentials generated by a click‐evoked vestibulocollic reflex. J Neurol Neurosurg Psychiatry 57: 190‐197, 1994.
 67. Convertino VA , Ryan KL , Rickards CA , Glorsky SL , Idris AH , Yannopoulos D , Metzger A , Lurie KG . Optimizing the respiratory pump: Harnessing inspiratory resistance to treat systemic hypotension. Respir Care 56: 846‐857, 2011.
 68. Costa F , Lavin P , Robertson D , Biaggioni I . Effect of neurovestibular stimulation on autonomic regulation. Clin Auton Res 5: 289‐293, 1995.
 69. Courville J , Faraco‐Cantin F . Topography of the olivo‐cerebellar projection. An experimental study in the cat with an autoradiographic tracing method. In: Courville J , Montigny Cd , Lamarre Y , editors. The Inferior Olivary Nucleus‐Anatomy and Physiology. New York: Raven, 1980.
 70. Crandall CG , Gonzalez‐Alonso J . Cardiovascular function in the heat‐stressed human. Acta Physiol (Oxf) 199: 407‐423, 2010.
 71. Cui J , Iwase S , Mano T , Katayama N , Mori S . Muscle sympathetic outflow during horizontal linear acceleration in humans. Am J Physiol Regul Integr Comp Physiol 281: R625‐634, 2001.
 72. Cui J , Iwase S , Mano T , Katayama N , Mori S . Sympathetic nerve response to muscle during anteroposterior acceleration in humans. Environ Med 42: 71‐75, 1998.
 73. Cui J , Mukai C , Iwase S , Sawasaki N , Kitazawa H , Mano T , Sugiyama Y , Wada Y . Response to vestibular stimulation of sympathetic outflow to muscle in humans. J Auton Nerv Syst 66: 154‐162, 1997.
 74. Cullen KE , Brooks JX , Jamali M , Carriot J , Massot C . Internal models of self‐motion: Computations that suppress vestibular reafference in early vestibular processing. Exp Brain Res 210: 377‐388, 2011.
 75. Dampney RA . Brain stem mechanisms in the control of arterial pressure. Clin Exp Hypertens 3: 379‐391, 1981.
 76. Dampney RA . The subretrofacial nucleus: Its pivotal role in cardiovascular regulation. News Physiol Sci 5: 63‐67, 1990.
 77. Dampney RA . The subretrofacial vasomotor nucleus ‐ anatomical, chemical and pharmacological properties and role in cardiovascular regulation. Prog Neurobiol 42: 197‐227, 1994.
 78. Dampney RA , Goodchild AK , McAllen RM . Vasomotor control by subretrofacial neurones in the rostral ventrolateral medulla. Can J Physiol Pharmacol 65: 1572‐1579, 1987.
 79. Dampney RA , Horiuchi J , Tagawa T , Fontes MA , Potts PD , Polson JW . Medullary and supramedullary mechanisms regulating sympathetic vasomotor tone. Acta Physiol Scand 177: 209‐218, 2003.
 80. Dampney RAL , McAllen RM . Differential control of sympathetic fibres supplying hindlimb skin and muscle by subretrofacial neurones in the cat. J Physiol 395: 41‐56, 1988.
 81. Dean C , Seagard JL , Hopp FA , Kampine JP . Differential control of sympathetic activity to kidney and skeletal muscle by ventral medullary neurons. J Auton Nerv Syst 37: 1‐10, 1992.
 82. Del Bo A , Sved AF , Reis DJ . Fastigial nucleus stimulation and concurrent activation of cardiovascular receptors; differentiate effects on arterial pressure, heart rate and vasopressin release. J Hypertens Suppl 2: S49‐51, 1984.
 83. Del Bo A , Sved AF , Reis DJ . Inhibitory influences from arterial baroreceptors on vasopressin release elicited by fastigial stimulation in rats. Circ Res 54: 248‐253, 1984.
 84. Destefino VJ , Reighard DA , Sugiyama Y , Suzuki T , Cotter LA , Larson MG , Gandhi NJ , Barman SM , Yates BJ . Responses of neurons in the rostral ventrolateral medulla to whole body rotations: Comparisons in decerebrate and conscious cats. J Appl Physiol 110: 1699‐1707, 2011.
 85. Dickman JD , Angelaki DE . Vestibular convergence patterns in vestibular nuclei neurons of alert primates. J Neurophysiol 88: 3518‐3533, 2002.
 86. Diedrich A , Porta A , Barbic F , Brychta RJ , Bonizzi P , Diedrich L , Cerutti S , Robertson D , Furlan R . Lateralization of expression of neural sympathetic activity to the vessels and effects of carotid baroreceptor stimulation. Am J Physiol Heart Circ Physiol 296: H1758‐1765, 2009.
 87. Dieterich M . Central vestibular disorders. J Neurol 254: 559‐568, 2007.
 88. Doba N , Reis DJ . Changes in regional blood flow and cardiodynamics evoked by electrical stimulation of the fastigial nucleus in the cat and their similarity to orthostatic reflexes. J Physiol 227: 729‐747, 1972.
 89. Doba N , Reis DJ . Role of the cerebellum and vestibular apparatus in regulation of orthostatic reflexes in the cat. Circ Res 34: 9‐18, 1974.
 90. Dulac S , Raymond JL , Sejnowski TJ , Lisberger SG . Learning and memory in the vestibulo‐ocular reflex. Annu Rev Neurosci 18: 409‐441, 1995.
 91. Dunne F , Barry D , Ferriss J , Grealy G , Murphy D . Changes in blood pressure during the normal menstrual cycle. Clin Sci (Lond) 81: 515‐518, 1991.
 92. Dyckman DJ , Monahan KD , Ray CA . Effect of baroreflex loading on the responsiveness of the vestibulosympathetic reflex in humans. J Appl Physiol 103: 1001‐1006, 2007.
 93. El Sayed K , Dawood T , Hammam E , Macefield VG . Evidence from bilateral recordings of sympathetic nerve activity for lateralisation of vestibular contributions to cardiovascular control. Exp Brain Res 221: 427‐436, 2012.
 94. Endo K , Thomson DB , Wilson VJ , Yamaguchi T , Yates BJ . Vertical vestibular input to and projections from the caudal parts of the vestibular nuclei of the decerebrate cat. J Neurophysiol 74: 428‐436, 1995.
 95. Essandoh LK , Duprez DA , Shepherd JT . Reflex constriction of human resistance vessels to head‐down neck flexion. Am J Physiol 64: 767‐770, 1988.
 96. Ezure K , Wilson VJ . Interaction of tonic neck and vestibular reflexes in the forelimb of the decerebrate cat. Exp Brain Res 54: 289‐292 1984.
 97. Fadel PJ , Raven PB . Human investigations into the arterial and cardiopulmonary baroreflexes during exercise. Exp Physiol 97: 39‐50, 2012.
 98. Fatouleh R , Macefield VG . Cardiorespiratory coupling of sympathetic outflow in humans: A comparison of respiratory and cardiac modulation of sympathetic nerve activity to skin and muscle. Exp Physiol 98: 1327‐1336, 2013.
 99. Favilla M , Ghelarducci B , Hill CD , Spyer KM . Vestibular inputs to the fastigial nucleus; evidence of convergence of macular and ampullar inputs. Pflugers Arch 384: 193‐201, 1980.
 100. Felder RB , Mifflin SW . Modulation of carotid sinus afferent input to nucleus tractus solitarius by parabrachial nucleus stimulation. Circ Res 63: 35‐49, 1988.
 101. Fernandez C , Goldberg JM . Physiology of peripheral neurons innervating otolith organs of the squirrel monkey. III. Response dynamics. J Neurophysiol 39: 996‐1008, 1976.
 102. Fernandez C , Goldberg JM . Physiology of peripheral neurons innervating semicircular canals of the squirrel monkey. II. Response to sinusoidal stimulation and dynamics of peripheral vestibular system. J Neurophysiol 34: 661‐675, 1971.
 103. Ferrari AU . Modifications of the cardiovascular system with aging. Am J Geriatr Cardiol 11: 30‐33, 2002.
 104. Fitzpatrick RC , Butler JE , Day BL . Resolving head rotation for human bipedalism. Curr Biol 16: 1509‐1514, 2006.
 105. Fitzpatrick RC , Day BL . Probing the human vestibular system with galvanic stimulation. J Appl Physiol 96: 2301‐2316, 2004.
 106. Fu Q , Iwase S , Niimi Y , Kamiya A , Michikami D , Mano T . Effects of aging on leg vein filling and venous compliance during low levels of lower body negative pressure in humans. Environ Med 43: 142‐145, 1999.
 107. Fu Q , Witkowski S , Levine BD . Vasoconstrictor reserve and sympathetic neural control of orthostasis. Circulation 110: 2931‐2937, 2004.
 108. Furlan R , Barbic F , Casella F , Severgnini G , Zenoni L , Mercieri A , Mangili R , Costantino G , Porta A . Neural autonomic control in orthostatic intolerance. Respir Physiol Neurobiol 169 (Suppl. 1): S17‐20, 2009.
 109. Furman JM , Balaban CD , Jacob RG , Marcus DA . Migraine‐anxiety related dizziness (MARD): A new disorder? J Neurol Neurosurg Psychiatry 76: 1‐8, 2005.
 110. Gandevia SC , Killian K , McKenzie DK , Crawford M , Allen GM , Gorman RB , Hales JP . Respiratory sensations, cardiovascular control, kinaesthesia and transcranial stimulation during paralysis in humans. J Physiol (Lond) 470: 85‐107, 1993.
 111. Gardner EP , Fuchs AF . Single‐unit responses to natural vestibular stimuli and eye movements in deep cerebellar nuclei of the alert rhesus monkey. J Neurophysiol 38: 627‐649, 1975.
 112. Gebber GL . Basis for phase relations between baroreceptor and sympathetic nervous discharge. Am J Physiol 230: 263‐270, 1976.
 113. Gebber GL , Barman SM . Rhythmogenesis in the sympathetic nervous system. Fed Proc 39: 2526‐2530, 1980.
 114. Gebber GL , Barman SM , Kocsis B . Coherence of medullary unit activity and sympathetic nerve discharge. Am J Physiol 259: R561‐571, 1990.
 115. Ghelarducci B . Responses of the cerebellar fastigial neurones to tilt. Pflugers Arch 344: 195‐206, 1973.
 116. Gilbey MP , Spyer KM . Essential organization of the sympathetic nervous system. Bailliere Clin Endocrinol Metab 7: 259‐278, 1993.
 117. Goldberg JM , Fernandez C . Vestibular mechanisms. Annu Rev Physiol 37: 129‐162, 1975.
 118. Goldberg JM , Fernández C . The vestibular system. In: Darian‐Smith I , editor. Handbook of Physiology Section I: The Nervous System Volume III, Sensory Processes, Part 2. Bethesda, MD: American Physiological Society, 1984, pp. 977‐1022.
 119. Goldberg JM , Smith CE , Fernandez C . Relation between discharge regularity and responses to externally applied galvanic currents in vestibular nerve afferents of the squirrel monkey. J Neurophysiol 51: 1236‐1256, 1984.
 120. Goldberg JM , Wilson VJ , Cullen KE , Angelaki DE , Broussard DM , Buttner‐Ennever J , Fukushima K , Minor LB . The Vestibular System: A Sixth Sense. Oxford University Press, 2012, p. 560.
 121. Golding JF , Gresty MA . Motion sickness. Curr Opin Neurol 18: 29‐34, 2005.
 122. Gootman PM , Cohen MI . Efferent splanchnic activity and systemic arterial pressure. Am J Physiol 219: 897‐903, 1970.
 123. Gootman PM , Cohen MI . Periodic modulation (cardiac and respiratory) of spontaneous and evoked sympathetic discharge. Acta Physiol Polonica 24: 97‐109, 1973.
 124. Gotoh TM , Fujiki N , Matsuda T , Gao S , Morita H . Roles of baroreflex and vestibulosympathetic reflex in controlling arterial blood pressure during gravitational stress in conscious rats. Am J Physiol Regul Integr Comp Physiol 286: R25‐R30, 2004.
 125. Gowen MF , Ogburn SW , Suzuki T , Sugiyama Y , Cotter LA , Yates BJ . Collateralization of projections from the rostral ventrolateral medulla to the rostral and caudal thoracic spinal cord in felines. Exp Brain Res 220: 121‐133, 2012.
 126. Granata AR , Ruggiero DA , Park DH , Joh TH , Reis DJ . Brain stem area with C1 epinephrine neurons mediates baroreflex vasodepressor responses. Am J Physiol 248: H547‐H567, 1985.
 127. Gresty M , Bronstein A , Brandt T , Dieterich M . Neurology of otolith function. Peripheral and central disorders. Brain 115: 647‐673, 1992.
 128. Grewal T , Dawood T , Hammam E , Kwok K , Macefield VG . Low‐frequency physiological activation of the vestibular utricle causes biphasic modulation of skin sympathetic nerve activity in humans. Exp Brain Res 220: 101‐108, 2012.
 129. Grewal T , James C , Macefield VG . Frequency‐dependent modulation of muscle sympathetic nerve activity by sinusoidal galvanic vestibular stimulation in human subjects. Exp Brain Res 197: 379‐386, 2009.
 130. Groenewegen HJ , Voogd J . The parasagittal zonation within the olivocerebellar projection. I. Climbing fiber distribution in the vermis of cat cerebellum. J Comp Neurol 174: 417‐488, 1977.
 131. Hamilton RB , Ellenberger H , Liskowsky D , Schneiderman N . Parabrachial area as mediator of bradycardia in rabbits. J Auton Nerv Syst 4: 261‐281, 1981.
 132. Hammam E , Dawood T , Macefield VG . Low‐frequency galvanic vestibular stimulation evokes two peaks of modulation in skin sympathetic nerve activity. Exp Brain Res 219: 441‐446, 2012.
 133. Hammam E , James C , Dawood T , Macefield VG . Low‐frequency sinusoidal galvanic stimulation of the left and right vestibular nerves reveals two peaks of modulation in muscle sympathetic nerve activity. Exp Brain Res 213: 507‐514, 2011.
 134. Hammam E , Kwok K , Macefield VG . Modulation of muscle sympathetic nerve activity by low‐frequency physiological activation of the vestibular utricle in awake humans. Exp Brain Res 230: 137‐142, 2013.
 135. Hargens AR , Richardson S . Cardiovascular adaptations, fluid shifts, and countermeasures related to space flight. Respir Physiol Neurobiol 169 (Suppl 1): S30‐33, 2009.
 136. Harms MP , Colier WN , Wieling W , Lenders JW , Secher NH , van Lieshout JJ . Orthostatic tolerance, cerebral oxygenation, and blood velocity in humans with sympathetic failure. Stroke 31: 1608‐1614, 2000.
 137. Heidenreich K , Weisend S , Fouad‐Tarazi F , White J . The incidence of coexistent autonomic and vestibular dysfunction in patients with postural dizziness. Am J Otolaryngol 30: 225‐229, 2009.
 138. Henry RT , Connor JD , Balaban CD . Nodulus‐uvula depressor response: Central GABA‐mediated inhibition of alpha‐adrenergic outflow. Am J Physiol 256: H1601‐H1608, 1989.
 139. Hilton SM , Spyer KM . Central nervous regulation of vascular resistance. Ann Rev Physiol 42: 399‐411, 1980.
 140. Hinghofer‐Szalkay H . Gravity, the hydrostatic indifference concept and the cardiovascular system. Eur J Appl Physiol 111: 163‐174, 2011.
 141. Holmes MJ , Cotter LA , Arendt HE , Cass SP , Yates BJ . Effects of lesions of the caudal cerebellar vermis on cardiovascular regulation in awake cats. Brain Res 938: 62‐72, 2002.
 142. Holstein GR , Friedrich VL, Jr , Kang T , Kukielka E , Martinelli GP . Direct projections from the caudal vestibular nuclei to the ventrolateral medulla in the rat. Neurosci 175: 104‐117, 2011.
 143. Hume KM , Ray CA . Sympathetic responses to head‐down rotations in humans. J Appl Physiol 86: 1971‐1976, 1999.
 144. Ichinose M , Nishiyasu T . Arterial baroreflex control of muscle sympathetic nerve activity under orthostatic stress in humans. Front Physiol 3: 314, 2012.
 145. Ishikawa T , Miyazawa T . Sympathetic responses evoked by vestibular stimulation and their interactions with somato‐sympathetic reflexes. J Auton Nerv Syst 1: 243‐254, 1980.
 146. Ishikawa T , Miyazawa T , Shimizu I , Tomita H . Similarity between vestibulo‐sympathetic response and supraspinal sympathetic reflex. Nihon Univ J Med 21: 201‐210, 1979.
 147. Jacob RG , Furman JM . Psychiatric consequences of vestibular dysfunction. Curr Opin Neurol 14: 41‐46, 2001.
 148. Jacob RG , Furman JM , Durrant JD , Turner SM . Panic, agoraphobia, and vestibular dysfunction. Am J Psychiatry 153: 503‐512, 1996.
 149. Jacob RG , Furman JM , Perel JM . Panic, phobia and vestibular dysfunction. In: Yates BJ , Miller AD , editors. Vestibular Autonomic Regulation. Boca Raton, FL: CRC Press, 1996.
 150. Jacob RG , Furman JMR , Clark DB , Durrant JD . Vestibular symptoms, panic and phobia: Overlap and possible relationships. Ann Clin Psychiatr 4: 163‐174, 1992.
 151. Jacobsen TN , Morgan BJ , Scherrer U , Vissing SF , Lange RA , Johnson N , Ring WS , Rahko PS , Hanson P , Victor RG . Relative contributions of cardiopulmonary and sinoaortic baroreflexes in causing sympathetic activation in the human skeletal muscle circulation during orthostatic stress. Circ Res 73: 367‐378, 1993.
 152. James C , Macefield VG . Competitive interactions between vestibular and cardiac rhythms in the modulation of muscle sympathetic nerve activity. Auton Neurosci 158: 127‐131, 2010.
 153. James C , Stathis A , Macefield VG . Vestibular and pulse‐related modulation of skin sympathetic nerve activity during sinusoidal galvanic vestibular stimulation in human subjects. Exp Brain Res 202: 291‐298, 2010.
 154. Janig W , Habler HJ . Neurophysiological analysis of target‐related sympathetic pathways–from animal to human: Similarities and differences. Acta Physiol Scand 177: 255‐274, 2003.
 155. Jänig W , McLachlan EM . Neurobiology of the autonomic nervous system. In: Mathias CJ , Bannister SR , editors. Autonomic Failure: A Textbook of Clinical Disorders of the Autonomic Nervous System. Oxford: Oxford Univ. Press, 2013, pp. 21‐34.
 156. Jänig W , McLachlan EM . Specialized functional pathways are the building blocks of the autonomic nervous system. J Autonom Nerv Syst 41: 3‐14, 1992.
 157. Jauregui‐Renaud K , Aw ST , Todd MJ , McGarvie LA , Halmagyi GM . Benign paroxysmal positional vertigo can interfere with the cardiac response to head‐down tilt. Otol Neurotol 26: 484‐488, 2005.
 158. Jauregui‐Renaud K , Hermosillo AG , Gomez A , Marquez MF , Cardenas M , Bronstein AM . Vestibular function interferes in cardiovascular reflexes. Arch Med Res 34: 200‐204, 2003.
 159. Jauregui‐Renaud K , Reynolds R , Bronstein AM , Gresty MA . Cardio‐respiratory responses evoked by transient linear acceleration. Aviat Space Environ Med 77: 114‐120, 2006.
 160. Jeske I , Morrison SF , Cravo SL , Reis DJ . Identification of baroreceptor reflex interneurons in the caudal ventrolateral medulla. Am J Physiol 264: R169‐R178, 1993.
 161. Jian BJ , Acernese AW , Lorenzo J , Card JP , Yates BJ . Afferent pathways to the region of the vestibular nuclei that participates in cardiovascular and respiratory control. Brain Res 1044: 241‐250, 2005.
 162. Jian BJ , Cotter LA , Emanuel BA , Cass SP , Yates BJ . Effects of bilateral vestibular lesions on orthostatic tolerance in awake cats. J Appl Physiol 86: 1552‐1560, 1999.
 163. Jian BJ , Shintani T , Emanuel BA , Yates BJ . Convergence of limb, visceral, and vertical semicircular canal or otolith inputs onto vestibular nucleus neurons. Exp Brain Res 144: 247‐257, 2002.
 164. Kanda K , Sato Y , Ikarashi K , Kawasaki T . Zonal organization of climbing fiber projections to the uvula in the cat. J Comp Neurol 279: 138‐148, 1989.
 165. Kasper J , Schor RH , Wilson VJ . Response of vestibular neurons to head rotations in vertical planes. I. Response to vestibular stimulation. J Neurophysiol 60: 1753‐1764, 1988.
 166. Kasper J , Schor RH , Wilson VJ . Response to vestibular neurons to head rotations in vertical planes. II. Response to neck stimulation and vestibular‐neck interaction. J Neurophysiol 60: 1765‐1778, 1988.
 167. Kaufmann H , Biaggioni I , Voustianiouk A , Diedrich A , Costa F , Clarke R , Gizzi M , Raphan T , Cohen B . Vestibular control of sympathetic activity. An otolith‐sympathetic reflex in humans. Exp Brain Res 143: 463‐469, 2002.
 168. Kerman IA , Emanuel BA , Yates BJ . Vestibular stimulation leads to distinct hemodynamic patterning. Am J Physiol Reg Integr Comp Physiol 279: R118‐125, 2000.
 169. Kerman IA , McAllen RM , Yates BJ . Patterning of sympathetic nerve activity in response to vestibular stimulation. Brain Res Bull 53: 11‐16, 2000.
 170. Kerman IA , Yates BJ . Regional and functional differences in the distribution of vestibulosympathetic reflexes. Am J Physiol 275: R824‐835, 1998.
 171. Kerman IA , Yates BJ , McAllen RM . Anatomic patterning in the expression of vestibulosympathetic reflexes. Am J Physiol Reg Integr Comp Physiol 279: R109‐117, 2000.
 172. Kleine JF , Wilden A , Siebold C , Glasauer S , Buttner U . Linear spatio‐temporal convergence in vestibular neurons of the primate nucleus fastigii. Neuroreport 10: 3915‐3921, 1999.
 173. Kondo M , Sears TA , Sadakane K , Nisimaru N . Vagal afferent projections to lobule VIIa of the rabbit cerebellar vermis related to cardiovascular control. Neurosci Res 30: 111‐117, 1998.
 174. Korte SM , Jaarsma D , Luiten PG , Bohus B . Mesencephalic cuneiform nucleus and its ascending and descending projections serve stress‐related cardiovascular responses in the rat. J Auton Nerv Syst 41: 157‐176, 1992.
 175. Krabbendam I , Jacobs LC , Lotgering FK , Spaanderman ME . Venous response to orthostatic stress. Am J Physiol Heart Circ Physiol 295: H1587‐1593, 2008.
 176. Krukoff TL , Harris KH , Jhamandas JH . Efferent projections from the parabrachial nucleus demonstrated with the anterograde tracer Phaseolus vulgaris leucoagglutinin. Brain Res Bull 30: 163‐172, 1993.
 177. Lackner JR , Dizio P . Space motion sickness. Exp Brain Res 175: 377‐399, 2006.
 178. Lawrence JE , Klein JC , Carter JR . Menstrual cycle elicits divergent forearm vascular responses to vestibular activation in humans. Auton Neurosci 154: 89‐93, 2010.
 179. Lee CM , Wood RH , Welsch MA . Influence of head‐down and lateral decubitus neck flexion on heart rate variability. J Appl Physiol 90: 127‐132, 2001.
 180. Lee TK , Lois JH , Troupe JH , Wilson TD , Yates BJ . Transneuronal tracing of neural pathways that regulate hindlimb muscle blood flow. Am J Physiol Reg Integr Comp Physiol 292: R1532‐1541, 2007.
 181. Len WB , Chan JYH . Glutamatergic projection to RVLM mediates suppression of reflex bradycardia by parabrachial nucleus. Am J Physiol Heart Circ Physiol 45: H1482‐H1492, 1999.
 182. Lisberger SG . The neural basis for learning of simple motor skills. Science 242: 728‐735, 1988.
 183. MacNeilage PR , Banks MS , DeAngelis GC , Angelaki DE . Vestibular heading discrimination and sensitivity to linear acceleration in head and world coordinates. J Neurosci 30: 9084‐9094, 2010.
 184. Mano T , Iwase S . Sympathetic nerve activity in hypotension and orthostatic intolerance. Acta Physiol Scand 177: 359‐365, 2003.
 185. Matsuda T , Gotoh TM , Tanaka K , Gao S , Morita H . Vestibulosympathetic reflex mediates the pressor response to hypergravity in conscious rats: Contribution of the diencephalon. Brain Res 1028: 140‐147, 2004.
 186. Matsukawa K . Central command: Control of cardiac sympathetic and vagal efferent nerve activity and the arterial baroreflex during spontaneous motor behaviour in animals. Exp Physiol 97: 20‐28, 2012.
 187. McAllen RM , Dampney RAL . Vasomotor neurons in the rostral ventrolateral medulla are organized topographically with respect to type of vascular bed but not body region. Neurosci Lett 110: 91‐96, 1990.
 188. McAllen RM , May CN . Differential drives from rostral ventrolateral medullary neurons to three identified sympathetic outflows. Am J Physiol Regul Integr Comp Physiol 267: R935‐R944, 1994.
 189. McCall AA , Moy JD , Puterbaugh SR , DeMayo WM , Yates BJ . Responses of vestibular nucleus neurons to inputs from the hindlimb are enhanced following a bilateral labyrinthectomy. J Appl Physiol 114: 742‐751, 2013.
 190. McCall AA , Yates BJ . Compensation following bilateral vestibular damage. Front Neurol 2: 88, 2011.
 191. McKenna KE . The autonomic neuroscience of sexual function. In: Mathias CJ , Bannister SR , editors. Autonomic Failure: A Textbook of Clinical Disorders of the Autonomic Nervous System. Oxford: Oxford Univ. Press, 2013, p. 119‐131.
 192. Megirian D , Manning JW . Input‐output relations in the vestibular system. Arch Ital Biol 105: 15‐30, 1967.
 193. Mifflin SW , Felder RB . Synaptic mechanisms regulating cardiovascular afferent inputs to solitary tract nucleus. Am J Physiol 259: H653‐661, 1990.
 194. Miles FA , Lisberger SG . Plasticity in the vestibulo‐ocular reflex: A new hypothesis. Ann Rev Neurosci 4: 273‐299, 1981.
 195. Miller DM , Cotter LA , Gandhi NJ , Schor RH , Cass SP , Huff NO , Raj SG , Shulman JA , Yates BJ . Responses of caudal vestibular nucleus neurons of conscious cats to rotations in vertical planes, before and after a bilateral vestibular neurectomy. Exp Brain Res 188: 175‐186, 2008.
 196. Minor LB , Goldberg JM . Vestibular‐nerve inputs to the vestibulo‐ocular reflex: A functional‐ablation study in the squirrel monkey. J Neurosci 11: 1636‐1648, 1991.
 197. Mitchell JH . Neural control of the circulation during exercise: Insights from the 1970–1971 Oxford studies. Exp Physiol 97: 14‐19, 2012.
 198. Mittelstaedt H . Somatic versus vestibular gravity reception in man. Ann NY Acad Sci 656: 124‐139, 1992.
 199. Miura M , Reis DJ . A blood pressure response from fastigial nucleus and its relay pathway in the brainstem. Am J Physiol 219: 1330‐1336, 1970.
 200. Miura M , Reis DJ . The paramedian reticular nucleus: A site of inhibitory interaction between projections from fastigial nucleus and carotid sinus nerve acting on blood pressure. J Physiol: 216 441‐460, 1971.
 201. Miura M , Takayama K . Circulatory and respiratory responses to glutamate stimulation of the lateral parabrachial nucleus of the cat. J Auton Nerv Syst 32: 121‐133, 1991.
 202. Miyazawa T , Ishikawa T . Cerebellar inhibitory action on vestibulo‐sympathetic responses. J Auton Nerv Syst 7: 185‐189, 1983.
 203. Monahan KD , Ray CA . Gender affects calf venous compliance at rest and during baroreceptor unloading in humans. Am J Physiol Heart Circ Physiol 286: H895‐901, 2004.
 204. Monahan KD , Ray CA . Limb neurovascular control during altered otolithic input in humans. J Physiol 538: 303‐308, 2002.
 205. Monahan KD , Ray CA . Vestibulosympathetic reflex during orthostatic challenge in aging humans. Am J Physiol Regul Integr Comp Physiol 283: R1027‐1032, 2002.
 206. Money KE . Motion sickness. Physiol Rev 50: 1‐39, 1970.
 207. Mori RL , Cotter LA , Arendt HE , Olsheski CJ , Yates BJ . Effects of bilateral vestibular nucleus lesions on cardiovascular regulation in conscious cats. J Appl Physiol 98: 526‐533, 2005.
 208. Morrison SF , Gebber GL . Axonal branching patterns and funicular trajectories of raphespinal sympathoinhibitory neurons. J Neurophysiol 53: 759‐772, 1985.
 209. Morrison SF , Gebber GL . Classification of raphe neurons with cardiac‐related activity. Am J Physiol 243: R49‐59, 1982.
 210. Morrison SF , Gebber GL . Raphe neurons with sympathetic‐related activity: Baroreceptor responses and spinal connections. Am J Physiol 246: R338‐348, 1984.
 211. Morrison SF , Nakamura K . Central neural pathways for thermoregulation. Front Biosci (Landmark Ed) 16: 74‐104, 2011.
 212. Moy JD , Miller DJ , Catanzaro MF , Boyle BM , Ogburn SW , Cotter LA , Yates BJ , McCall AA . Responses of neurons in the caudal medullary lateral tegmental field to visceral inputs and vestibular stimulation in vertical planes. Am J Physiol Regul Integr Comp Physiol 303: R929–R940, 2012.
 213. Nakamoto T , Matsukawa K , Liang N , Wakasugi R , Wilson LB , Horiuchi J . Coactivation of renal sympathetic neurons and somatic motor neurons by chemical stimulation of the midbrain ventral tegmental area. J Appl Physiol 110: 1342‐1353, 2011.
 214. Nalivaiko E , Blessing WW . Potential role of medullary raphe‐spinal neurons in cutaneous vasoconstriction: An in vivo electrophysiological study. J Neurophysiol 87: 901‐911, 2002.
 215. Ng AV , Johnson DG , Callister R , Seals DR . Muscle sympathetic nerve activity during postural change in healthy young and older adults. Clin Auton Res 5: 57‐60, 1995.
 216. Nisimaru N . Cardiovascular modules in the cerebellum. Jpn J Physiol 54: 431‐448, 2004.
 217. Nisimaru N , Katayama S . Projection of cardiovascular afferents to the lateral nodulus‐uvula of the cerebellum in rabbits. Neurosci Res 21: 343‐350, 1995.
 218. Nisimaru N , Watanabe Y . A depressant area in the lateral nodulus‐uvula of the cerebellum for renal sympathetic nerve activity and systemic blood pressure in the rabbit. Neurosci Res 3: 177‐181, 1985.
 219. Nisimaru N , Yamamoto M . Depressant action of the posterior lobe of the cerebellum upon renal sympathetic nerve activity. Brain Res 133: 371‐375, 1977.
 220. Normand H , Etard O , Denise P . Otolithic and tonic neck receptors control of limb blood flow in humans. J Appl Physiol 82: 1734‐1738, 1997.
 221. Okahara K , Nisimaru N . Climbing fiber responses evoked in lobule VII of the posterior cerebellum from a vagal nerve in rabbits. Neurosci Res 12: 232‐239, 1991.
 222. Ootsuka Y , Blessing WW , McAllen RM . Inhibition of rostral medullary raphe neurons prevents cold‐induced activity in sympathetic nerves to rat tail and rabbit ear arteries. Neurosci Lett 357: 58‐62, 2004.
 223. Paintal AS . Vagal sensory receptors and their reflex effects. Physiol Rev 53: 159‐227, 1973.
 224. Pan PS , Zhang YS , Chen YZ . Role of nucleus vestibularis medialis in vestibulo‐sympathetic response in rats. Acta Physiol Sin 43: 184‐188, 1991.
 225. Paton JF , Gilbey MP . Effect of anesthetic on sympathetic responses evoked from cerebellar uvula in decerebrate cats. Am J Physiol 263: H1285‐1291, 1992.
 226. Paton JF , La Noce A , Sykes RM , Sebastiani L , Bagnoli P , Ghelarducci B , Bradley DJ . Efferent connections of lobule IX of the posterior cerebellar cortex in the rabbit—some functional considerations. J Auton Nerv Syst 36: 209‐224, 1991.
 227. Paton JFR , Silva‐Carvalho L , Thompson CS , Spyer KM . Nucleus tractus solitarius as mediator of evoked parabrachial cariovascular responses in the decerebrate rabbit. J Physiol 428: 693‐705, 1990.
 228. Patterson SW , Starling EH . On the mechanical factors which determine the output of the ventricles. J Physiol 48: 357‐379, 1914.
 229. Pilowsky PM , Goodchild AK . Baroreceptor reflex pathways and neurotransmitters: 10 years on. J Hypertens 20: 1675‐1688, 2002.
 230. Pitman JR , Yolton RL . Etiology and treatment of motion sickness: A review. J Am Optometric Assoc 54: 31‐38, 1983.
 231. Pompeiano O . Vestibulospinal relations: Vestibular influences on gamma motoneurons and primary afferents. Prog Brain Res 37: 197‐232, 1972.
 232. Porter JD , Balaban CD . Connections between the vestibular nuclei and brain stem regions that mediate autonomic function in the rat. J Vestib Res 7: 63‐76, 1997.
 233. Precht W , Volkind R , Maeda M , Giretti ML . The effects of stimulating the cerebellar nodulus in the cat on the responses of vestibular neurons. Neuroscience 1: 301‐312, 1976.
 234. Radtke A , Popov K , Bronstein AM , Gresty MA . Evidence for a vestibulo‐cardiac reflex in man. Lancet 356: 736‐737, 2000.
 235. Radtke A , Popov K , Bronstein AM , Gresty MA . Vestibulo‐autonomic control in man: Short‐ and long‐latency vestibular effects on cardiovascular function. J Vestib Res 13: 25‐37, 2003.
 236. Ray CA . Effect of gender on vestibular sympathoexcitation. Am J Physiol Regul Integr Comp Physiol 279: R1330‐R1333, 2000.
 237. Ray CA . Interaction of the vestibular system and baroreflexes on sympathetic nerve activity in humans. Am J Physiol Heart Circ Physiol 279: H2399‐H2404, 2000.
 238. Ray CA , Hume KM . Neck afferents and muscle sympathetic activity in humans: Implications for the vestibulosympathetic reflex. J Appl Physiol 84: 450‐453, 1998.
 239. Ray CA , Hume KM , Shortt TL . Skin sympathetic outflow during head‐down neck flexion in humans. Am J Physiol 273: R1142‐1146, 1997.
 240. Ray CA , Hume KM , Steele SL . Sympathetic nerve activity during natural stimulation of horizontal semicircular canals in humans. Am J Physiol 275: R1274‐1278, 1998.
 241. Rea RF , Wallin BG . Sympathetic nerve activity in arm and leg muscles during lower body negative pressure in humans. J Appl Physiol 66: 2778‐2781, 1989.
 242. Reason JT , Brandt JJ . Motion Sickness. London: Academic Press, 1975.
 243. Reis DJ , Ledoux JE . Some central neural mechanisms governing resting and behaviorally coupled control of blood pressure. Circulation 76: I2‐9, 1987.
 244. Reis DJ , Ross CA , Ruggiero DA , Granata AR , Joh TH . Role of adrenaline neurons of ventrolateral medulla (the C1 group) in the tonic and phasic control of arterial pressure. Clin Exp Hypertens A 6: 221‐241, 1984.
 245. Rowland TW . The circulatory response to exercise: Role of the peripheral pump. Int J Sports Med 22: 558‐565, 2001.
 246. Ruggiero DA , Mtui EP , Otake K , Anwar M . Vestibular afferents to the dorsal vagal complex: Substrate for vestibular‐autonomic interactions in the rat. Brain Res 743: 294‐302, 1996.
 247. Ruggiero DA , Regunathan S , Wang H , Milner TA , Reis DJ . Immunocytochemical localization of an imidazoline receptor protein in the central nervous system. Brain Res 780: 270‐293, 1998.
 248. Ruggiero DA , Underwood MD , Mann JJ , Anwar M , Arango V . The human nucleus of the solitary tract: Visceral pathways revealed with an ‘‘in vitro’' postmortem tracing method. J Autonom Nerv Syst 79: 181‐190, 2000.
 249. Rushmer RF. Cardiovascular Dynamics. Philadelphia: Saunders, 1976.
 250. Sadakane K , Kondo M , Nisimaru N . Direct projection from the cardiovascular control region of the cerebellar cortex, the lateral nodulus‐uvula, to the brainstem in rabbits. Neurosci Res 36: 15‐26, 2000.
 251. Sagawa K . Baroreflex control of systemic arterial pressure and vascular bed. In: Shepherd JT , Abboud FM , editors. Handbook of Physiology Section 2: Circulation Volume III: Peripheral Circulation and Organ Blood Flow, Part 2. Bethesa, MD: American Physiological Society, 1983, pp. 453‐496.
 252. Sauder CL , Leonard TO , Ray CA . Greater sensitivity of the vestibulosympathetic reflex in the upright posture in humans. J Appl Physiol 105: 65‐69, 2012.
 253. Schramm LP , Strack AM , Platt KB , Loewy AD . Peripheral and central pathways regulating the kidney ‐ a study using pseudorabies virus. Brain Res 616: 251‐262, 1993.
 254. Seagard JL , Hopp FA , Drummond HA , Van Wynsberghe DM . Selective contribution of two types of carotid sinus baroreceptors to the control of blood pressure. Circ Res 72: 1011‐1022, 1993.
 255. Serrador JM , Schlegel TT , Black FO , Wood SJ . Vestibular effects on cerebral blood flow. BMC Neurosci 10: 119, 2009.
 256. Shaikh AG , Ghasia FF , Dickman JD , Angelaki DE . Properties of cerebellar fastigial neurons during translation, rotation, and eye movements. J Neurophysiol 93: 853‐863, 2005.
 257. Shaikh AG , Meng H , Angelaki DE . Multiple reference frames for motion in the primate cerebellum. J Neurosci 24: 4491‐4497, 2004.
 258. Shojaku H , Sato Y , Ikarashi K , Kawasaki T . Topographical distribution of Purkinje cells in the uvula and the nodulus projecting to the vestibular nuclei in cats. Brain Res 416: 100‐112, 1987.
 259. Shortt TL , Ray CA . Sympathetic and vascular responses to head‐down neck flexion in humans. Am J Physiol 272: H1780‐1784, 1997.
 260. Siebold C , Glonti L , Glasauer S , Buttner U . Rostral fastigial nucleus activity in the alert monkey during three‐dimensional passive head movements. J Neurophysiol 77: 1432‐1446, 1997.
 261. Siebold C , Kleine JF , Glonti L , Tchelidze T , Buttner U . Fastigial nucleus activity during different frequencies and orientations of vertical vestibular stimulation in the monkey. J Neurophysiol 82: 34‐41, 1999.
 262. Silva‐Carvalho L , Paton JF , Goldsmith GE , Spyer KM . The effects of electrical stimulation of lobule IXb of the posterior cerebellar vermis on neurones within the rostral ventrolateral medulla in the anaesthetised cat. J Autonom Nerv Syst 36: 97‐106, 1991.
 263. Silvoniemi P . Vestibular neuronitis. An otoneurological evaluation. Acta Otolaryngol Suppl 453: 1‐72, 1988.
 264. Smith JE , Jansen AS , Gilbey MP , Loewy AD . CNS cell groups projecting to sympathetic outflow of tail artery: Neural circuits involved in heat loss in the rat. Brain Res 786: 153‐164, 1998.
 265. Smith OA, Jr , Clarke NP . Central autonomic pathways. A study in functional neuroanatomy. J Comp Neurol 122: 399‐406, 1964.
 266. Smith OA, Jr , Nathan MA . Inhibition of the carotid sinus reflex by stimulation of the inferior olive. Science 154: 674‐675, 1966.
 267. Somana R , Walberg F . Cerebellar afferents from the nucleus of the solitary tract. Neurosci Lett 11: 41‐47, 1979.
 268. Spiegel EA . Effect of labyrinthine reflexes on the vegetative nervous system. Arch Otolaryngol 44: 61‐72, 1946.
 269. Spiegel EA , Démétriades TD . Der Einfluss des Vestibular‐apparates auf das Gefässsystem. Pflügers Arch ges Physiol 196 185‐188, 1922.
 270. Spyer KM . Annual review prize lecture ‐ central nervous mechanisms contributing to cardiovascular control. J Physiol 474: 1‐19, 1994.
 271. Spyer KM . Neural organisation and control of the baroreceptor reflex. Rev Physiol Biochem Pharmacol 88: 23‐124, 1981.
 272. Stanojevic M . Responses of cerebellar fastigial neurons to neck and macular vestibular inputs. Pflugers Archiv 391: 267‐272, 1981.
 273. Stanojevic M , Erway L , Ghelarducci B , Pompeiano O , Willis WD, Jr . A comparison of the response characteristics of cerebellar fastigial and vermal cortex neurons to sinusoidal stimulation of macular vestibular receptors. Pflugers Archiv 385: 95‐104, 1980.
 274. Starling EH . The Linacre Lectue on the Law of the Heart. London: Longmans, Green, 1918.
 275. Steinbacher BC, Jr , Yates BJ . Brain‐stem integrative sites for vestibulo‐sympathetic reflexes. Ann N Y Acad Sci 781: 700‐702, 1996.
 276. Steinbacher BC , Yates BJ . Brainstem interneurons necessary for vestibular influences on sympathetic outflow. Brain Res 720: 204‐210, 1996.
 277. Steinbacher BC , Yates BJ . Processing of vestibular and other inputs by the caudal ventrolateral medullary reticular formation. Am J Physiol Regul Integr Comp Physiol 271: R1070‐R1077, 1996.
 278. Stocker SD , Steinbacher BC , Balaban CD , Yates BJ . Connections of the caudal ventrolateral medullary reticular formation in the cat brainstem. Exp Brain Res 116: 270‐282, 1997.
 279. Strack AM , Sawyer WB , Marubio LM , Loewy AD . Spinal origin of sympathetic preganglionic neurons in the rat. Brain Res 455: 187‐191, 1988.
 280. Sugiyama Y , Suzuki T , DeStefino VJ , Yates BJ . Integrative responses of neurons in nucleus tractus solitarius to visceral afferent stimulation and vestibular stimulation in vertical planes. Am J Physiol Regul Integr Comp Physiol 301: R1380‐1390, 2011.
 281. Sugiyama Y , Suzuki T , Yates BJ . Role of the rostral ventrolateral medulla (RVLM) in the patterning of vestibular system influences on sympathetic nervous system outflow to the upper and lower body. Exp Brain Res 210: 515‐527, 2011.
 282. Sundlof G , Wallin BG . The variability of muscle nerve sympathetic activity in resting recumbent man. J Physiol 272: 383‐397, 1977.
 283. Sved AF , Ito S , Madden CJ , Stocker SD , Yajima Y . Excitatory inputs to the RVLM in the context of the baroreceptor reflex. Ann NY Acad Sci 940: 247‐258, 2001.
 284. Sved AF , Ito S , Sved JC . Brainstem mechanisms of hypertension: Role of the rostral ventrolateral medulla. Curr Hypertens Rep 5: 262‐268, 2003.
 285. Sverrisdottir YB , Rundqvist B , Elam M . Relative burst amplitude in human muscle sympathetic nerve activity: A sensitive indicator of altered sympathetic traffic. Clin Auton Res 8: 95‐100, 1998.
 286. Tang PC , Gernandt BE . Autonomic responses to vestibular stimulation. Exp Neurol 24: 558‐578, 1969.
 287. Thoren PN . Atrial receptors with nonmedullated vagal afferents in the cat. Discharge frequency and pattern in relation to atrial pressure. Circ Res 38: 357‐362, 1976.
 288. Uchino Y . Effects of electric stimulation of the vestibular nerve on sympathetic nervous activities. Shinkei Kenkyu No Shimpo 14: 129‐133, 1970.
 289. Uchino Y , Kudo N , Tsuda K , Iwamura Y . Vestibular inhibition of sympathetic nerve activities. Brain Res 22: 195‐206, 1970.
 290. Ugolini G . Transneuronal transfer of herpes simplex virus type 1 (HSV 1) from mixed limb nerves to the CNS. I. Sequence of transfer from sensory, motor, and sympathetic nerve fibres to the spinal cord. J Comp Neurol 326: 527‐548, 1992.
 291. Valbo AH , Hagbath K‐E , Wallin BG . Microneurography: How the techniques developed and its role in the investigation of the sympathetic nervous system. J Appl Physiol 96: 1262‐1269, 2004.
 292. van Lieshout JJ , Wieling W , Wesseling KH , Endert E , Karemaker JM . Orthostatic hypotension caused by sympathectomies performed for hyperhidrosis. Neth J Med 36: 53‐57, 1990.
 293. Vertes RP , Crane AM . Descending projections of the posterior nucleus of the hypothalamus: Phaseolus vulgaris leucoagglutinin analysis in the rat. J Comp Neurol 374: 607‐631, 1996.
 294. Vibert D , Safran A . Subjective visual vertical in peripheral unilateral vestibular diseases. J Vestib Res 9: 145‐152, 1999.
 295. Vissing SF , Scherrer U , Victor RG . Increase of sympathetic discharge to skeletal muscle but not to skin during mild lower body negative pressure in humans. J Physiol 481 (Pt 1): 233‐241, 1994.
 296. Voustianiouk A , Kaufmann H , Diedrich A , Raphan T , Biaggioni I , Macdougall H , Ogorodnikov D , Cohen B . Electrical activation of the human vestibulo‐sympathetic reflex. Exp Brain Res 171: 251‐261, 2006.
 297. Walberg F , Dietrichs E . The interconnection between the vestibular nuclei and the nodulus: A study of reciprocity. Brain Res 449: 47‐53, 1988.
 298. Waldrop TG , Eldridge FL , Iwamoto GA , Mitchell JH . Central neural control of respiration and circulation during exercise. In: Rowell LB , Shepherd JT , editors. Handbook of Physiology, Section 12, Exercise: Regulation and Integration of Multiple Systems. New York: Oxford University Press, 1996.
 299. Waldrop TG , Iwamoto GA . Cardiovascular responses to chemical stimulation of the inferior olive in the cat. Brain Res Bull 26: 667‐670, 1991.
 300. Wang W , Han HY , Zucker IH . Depressed baroreflex in heart failure is not due to structural change in carotid sinus nerve fibers. J Auton Nerv Syst 57: 101‐108, 1996.
 301. Watenpaugh DE , Cothron AV , Wasmund SL , Wasmund WL , Carter R, 3rd , Muenter NK , Smith ML . Do vestibular otolith organs participate in human orthostatic blood pressure control? Auton Neurosci 100: 77‐83, 2002.
 302. Watenpaugh DE , Hargens AR . The cardiovascular system in microgravity. In: Fregley MJ , Blatteis CM , editors. Handbook of Physiology Section 4: Environmental Physiology. New York: Oxford University Press, 1996, pp. 631‐674.
 303. Wearne S , Raphan T , Waespe W , Cohen B . Control of the three‐dimensional dynamic characteristics of the angular vestibulo‐ocular reflex by the nodulus and uvula. In: Dezeeuw CI , Strata P , Voogd J , editors. Cerebellum: From Structure to Control. Amsterdam: Elsevier, 1997, p. 321‐334.
 304. Wieling W , Krediet CT , van Dijk N , Linzer M , Tschakovsky ME . Initial orthostatic hypotension: Review of a forgotten condition. Clin Sci (Lond) 112: 157‐165, 2007.
 305. Williamson JW . The relevance of central command for the neural cardiovascular control of exercise. Exp Physiol 95: 1043‐1048, 2010.
 306. Wilson TD , Cotter LA , Draper JA , Misra SP , Rice CD , Cass SP , Yates BJ . Effects of postural changes and removal of vestibular inputs on blood flow to the head of conscious felines. J Appl Physiol 100: 1475‐1482, 2006.
 307. Wilson TD , Cotter LA , Draper JA , Misra SP , Rice CD , Cass SP , Yates BJ . Vestibular inputs elicit patterned changes in limb blood flow in conscious cats. J Physiol 575: 671‐684, 2006.
 308. Wilson TD , Serrador JM , Shoemaker JK . Head position modifies cerebrovascular response to orthostatic stress. Brain Res 961: 261‐268, 2003.
 309. Wilson TE , Kuipers NT , McHugh EA , Ray CA . Vestibular activation does not influence skin sympathetic nerve responses during whole body heating. J Appl Physiol 97: 540‐544, 2004.
 310. Wilson VJ . Vestibulospinal and neck reflexes interaction in the vestibular nuclei. Arch Ital Biol 129: 43‐52, 1991.
 311. Wilson VJ , Schor RH , Suzuki I , Park BR . Spatial organization of neck and vestibular reflexes acting on the forelimbs of the decerebrate cat. J Neurophysiol 55: 514‐526, 1986.
 312. Woodring SF , Rossiter CD , Yates BJ . Pressor response elicited by nose‐up vestibular stimulation in cats. Exp Brain Res 113: 165‐168, 1997.
 313. Yates BJ . Vestibular influences on the autonomic nervous system. Ann NY Acad Sci 781: 458‐473, 1996.
 314. Yates BJ . Motion sickness. In: Binder MD , Hirokawa N , Windhorst U , editors. Encyclopedia of Neuroscience. Heidelberg: Springer‐Verlag, 2009, pp. 2410‐2413.
 315. Yates BJ , Aoki M , Burchill P , Bronstein AM , Gresty MA . Cardiovascular responses elicited by linear acceleration in humans. Exp Brain Res 125: 476‐484, 1999.
 316. Yates BJ , Balaban CD , Miller AD , Endo K , Yamaguchi Y . Vestibular inputs to the lateral tegmental field of the cat: Potential role in autonomic control. Brain Res 689: 197‐206, 1995.
 317. Yates BJ , Bronstein AM . Vestibular system influences on respiratory muscle activity and cardiovascular functions. In: Mathias CJ , Bannister SR , editors. Autonomic Failure: A Textbook of Clinical Disorders of the Autonomic Nervous System. Oxford: Oxford Univ. Press, 2013, pp. 97‐107.
 318. Yates BJ , Goto T , Bolton PS . Responses of neurons in the caudal medullary raphe nuclei of the cat to stimulation of the vestibular nerve. Exp Brain Res 89: 323‐332, 1992.
 319. Yates BJ , Goto T , Bolton PS . Responses of neurons in the rostral ventrolateral medulla of the cat to natural vestibular stimulation. Brain Res 601: 255‐264, 1993.
 320. Yates BJ , Goto T , Kerman I , Bolton PS . Responses of caudal medullary raphe neurons to natural vestibular stimulation. J Neurophysiol 70: 938‐946, 1993.
 321. Yates BJ , Grélot L , Kerman IA , Balaban CD , Jakus J , Miller AD . Organization of vestibular inputs to nucleus tractus solitarius and adjacent structures in cat brain stem. Am J Physiol 267: R974‐983, 1994.
 322. Yates BJ , Holmes MJ , Jian BJ . Plastic changes in processing of graviceptive signals during spaceflight potentially contribute to postflight orthostatic intolerance. J Vestib Res 13: 395‐404, 2003.
 323. Yates BJ , Jakus J , Miller AD . Vestibular effects on respiratory outflow in the decerebrate cat. Brain Res 629: 209‐217, 1993.
 324. Yates BJ , Jian BJ , Cotter LA , Cass SP . Responses of vestibular nucleus neurons to tilt following chronic bilateral removal of vestibular inputs. Exp Brain Res 130: 151‐158, 2000.
 325. Yates BJ , Kerman IA . Post‐spaceflight orthostatic intolerance: Possible relationship to microgravity‐induced plasticity in the vestibular system. Brain Res Rev 28: 73‐82, 1998.
 326. Yates BJ , Miller AD . Physiological evidence that the vestibular system participates in autonomic and respiratory control. J Vestib Res 8: 17‐25, 1998.
 327. Yates BJ , Miller AD . Properties of sympathetic reflexes elicited by natural vestibular stimulation: Implications for cardiovascular control. J Neurophysiol 71: 2087‐2092, 1994.
 328. Yates BJ , Siniaia MS , Miller AD . Descending pathways necessary for vestibular influences on sympathetic and inspiratory outflow. Am J Physiol Regul Integr Comp Physiol 268: R1381‐R1385, 1995.
 329. Yates BJ , Wilson TD . Vestibulo‐autonomic responses. In: Squire LR , editor. Encyclopedia of Neuroscience. Oxford: Academic Press, 2009, pp. 133‐138.
 330. Yates BJ , Yamagata Y , Bolton PS . The ventrolateral medulla of the cat mediates vestibulosympathetic reflexes. Brain Res 552: 265‐272, 1991.
 331. Yavorcik KJ , Reighard DA , Misra SP , Cotter LA , Cass SP , Wilson TD , Yates BJ . Effects of postural changes and removal of vestibular inputs on blood flow to and from the hindlimb of conscious felines. Am J Physiol Regul Integr Comp Physiol 297: R1777‐1784, 2009.
 332. Zhong S , Huang ZS , Gebber GL , Barman SM . Role of the brain stem in generating the 2‐ to 6‐Hz oscillation in sympathetic nerve discharge. Am J Physiol 265: R1026‐1035, 1993.
 333. Zhou W , Tang BF , King WM . Responses of rostral fastigial neurons to linear acceleration in an alert monkey. Exp Brain Res 139: 111‐115, 2001.

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Bill J. Yates, Philip S. Bolton, Vaughan G. Macefield. Vestibulo‐Sympathetic Responses. Compr Physiol 2014, 4: 851-887. doi: 10.1002/cphy.c130041