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Plasticity in Adult Avian Central Nervous System: Possible Relation Between Hormones, Learning, and Brain Repair

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Abstract

The sections in this article are:

1 Description of Song
2 Song Learning in Birds
3 Temporal Constraints on Learning: Possible Role for Hormones
4 Hypoglossal Dominance: Animal Example of Handedness
5 Central Pathways for Song Control
6 Hemispheric Dominance and its Reversal
7 Sexual Dimorphism in Brain Anatomy and Function
8 Ontogeny of a Sexual Dimorphism: Early Hormonal Effects
9 Peripheral Effects of Testosterone
10 Testosterone Induces Dendritic Growth and Synaptogenesis in Adulthood
11 Space for Learned Skill
12 Seasonal Effects on Male Central Pathways for Song Control
13 Neurogenesis in Adulthood
14 Neuronal Replacement
15 Significance of Neuronal Replacement
16 Conclusion
Figure 1. Figure 1.

Sound spectrograph of fragment of adult male canary song showing 3 different syllable types. Repetition of same syllable forms phrase. Syllables are composed of 1 or more elements, preceded by silent gap. Each element is represented by a fundamental frequency and 1 or more harmonics. Calibration bar, 0.5 s.

From Nottebohm and Nottebohm 104.
Figure 2. Figure 2.

Monthly changes in blood testosterone levels and song. A: blood testosterone (T) levels in monthly samples from a group of 6 adult male canaries. First sample was taken in May when birds were 12 mo; last sample was taken the following May when birds were 24 mo. Vertical bars, SE. B: mean size of song repertoires measured in numbers of syllables from recordings obtained from same birds as in A. Mean size of song repertoire shows 2 significant increases: during September/October and during March. C: mean number of new syllable types produced each month by same birds shows waves of new syllable addition with peaks in September and March. Net increase in total syllable numbers is smaller than addition of new syllables because some older syllables are lost. Periods of enhanced song learning seem to be preceded by drop in blood testosterone levels. (F. Nottebohm, M. E. Nottebohm, L. Crane, and J. C. Wingfield, unpublished observations).

Figure 3. Figure 3.

A: ventral view of larynx, trachea, and bronchi of adult canary. Vocal organ, or syrinx, has its own complement of muscles and is surrounded by interclavicular air sac (icas), which is part of respiratory system. Branch of hypoglossal nerve (XII), cervicalis descendens inferior (cds) or tracheosyringealis, innervates muscles of ipsilateral syringeal half. Recurrens branch of vagus nerve (RX) innervates nearby crop (not shown). bd, Bronchidesmus; ca, cerivcalis ascendens branch of XII nerve; gcs, cervical superior and gp, petrosum ganglia of IX nerve; h′, h″, hypoglossal and c, cervical roots of XII nerve; m st tr, sternotrachealis muscle; m tr I, tracheolateralis muscle. B: longitudinal section through syrinx. Left muscle mass is heavier than its right counterpart. Sound production is thought to result from periodic interruptions of airflow during expiration as internal tympaniform membrane (ti) oscillates in and out of bronchial lumen, possibly locked in step with local air turbulence. Bronchidesmal membrane anchors medial wall of bronchi to dorsal wall of interclavicular air sac. T, tympanum; b1, b2, and b3, bronchial half rings; LB, left bronchus; RB, right bronchus; le, labium externum; pe, pessulus; sl, semilunar membrane; M, intrinsic syringeal muscles.

From Nottebohm and Nottebohm 104.
Figure 4. Figure 4.

Two adult male canaries recorded while producing stable, adult song (trace A). Subsequently bird 1 had its right syringeal half denervated and bird 15 had its left syringeal half denervated (trace B). Song of bird 1 remained unaltered; postoperative song of bird 15 suffered loss of most syllable types, which were replaced by silent gaps, clicks, and other modified sounds.

From Nottebohm and Nottebohm 104.
Figure 5. Figure 5.

Schematic sagittal view of brain of adult male canary. Field L, highest forebrain auditory projection sends fibers that appose ventrally to nucleus hyperstriatum ventralis pars caudalis (HVc); HVc projects to nucleus robustus archistrialis (RA), which sends direct pathway to motoneurons of nucleus nervi hypoglossi (nXIIts) that innervate muscles of syrinx. All projections are ipsilateral. Distance from rostral to caudal end of brain, 13 mm. Cb, cerebellum.

Figure 6. Figure 6.

Two adult male canaries recorded while producing stable, adult song (trace A). Subsequently bird 54 had its right HVc lesioned and bird 97 had its left HVc lesioned. Both lesions were complete, resulting in elimination of HVc on one side (trace B). Song of bird 54 became unstable after the lesion, with intrusion of other independent sounds; syllable and phrase structure otherwise remained recognizable. Postoperative song of bird 97 lost virtually all of its preoperative syllable and phrase structure.

From Nottebohm et al. 106.
Figure 7. Figure 7.

Typical type IV RA cells of female (top) and male (bottom) canaries shown from behind, with reference to midline (M) and lateral (L) edge of brain. Same cells are then turned 90° and viewed from side, with reference to anterior (A) and posterior (P) end of brain. Dendritic trees were drawn with a motor‐driven microscope stage yoked to a computer, which allowed a complete threedimensional reconstruction of dendrites and their relative positions. Dotted lines, boundaries between contiguous 100 μm‐thick tissue sections used for reconstruction. Dorsal (D) and ventral (V) coordinates are same for 2 views of same cell. Male dendrites reach farther away from soma than do female dendrites.

From De Voogd and Nottebohm 31.
Figure 8. Figure 8.

Normal song development in male canaries, kept under photoperiod conditions of New York state, shown as horizontal progression from subsong (SS) to plastic song (PS) to full song (FS). FS is stable song that adult canaries sing during breeding season. At end of breeding season PS recurs. HVc volume grows during the time song is first acquired and shrinks to that of 3‐ to 4‐mo‐old canary in late summer after breeding season is over and song becomes plastic again. Vertical axis, volume of nucleus HVc ± 1 SD. Open circles, samples of 4 birds killed at age shown on horizontal axis; filled circles, samples of 9 and 12 birds killed at 12 and 17 mo, respectively; open diamonds, samples of 10, 9, and 8 birds killed at end of their 1st, 2nd, and 3rd breeding seasons, respectively.

Figure 9. Figure 9.

Sound spectrographs of 3 recordings from same bird. A: plastic song when bird was 4 mo old. B: plastic song produced in late summer (September) after end of its 1st breeding season. C: stable song during preceding May when bird was 12 mo old and in full reproductive condition. In A and B song syllables are repeated in wavering, unstable fashion; in C syllables are virtual carbon copies of each other. Calibration bar, 0.5 s.

Figure 10. Figure 10.

Camera lucida tracing of dendritic and axonal processes of HVc cell labeled with horseradish peroxidase andthymidine. Heavy lines, dendrites; light lines, axons. Boundaries of HVc: solid line, ventricle; broken line, fibrous lamina. Calibration bar, 100 μm. D and M, dorsal and medial reaches of the brain. [From Paton and Nottebohm 111. Copyright 1984 by the American Association for the Advancement of Science.]

3H
Figure 11. Figure 11.

Anatomy of HVc cell bodies labeled with horseradish peroxidase and (3H)thymidine. Seperate photographs were taken of same field but were focused first at level of cell itself (A and C) and then at level of exposed silver grains in layer of emulsion above cell (B and D). A and B, same cell; C and D, same cell. Calibration bar, 10 μm. (From Paton and Nottebohm 111. Copyright 1984 by the American Association for the Advancement of Science.)

Figure 12. Figure 12.

13: Distribution of labeled cells in same frontal brain section from an adult female canary killed 26 days after last of series of 28 injections of (3H)thymidine spaced 12 h apart. Each dot corresponds to a labeled cell; HVc is demarcated by broken line curving under lateral ventricle (V) of forebrain. 1: Labeled neurons. 2: Labeled glia. 3: Labeled endothelial cells. 4: Rostral section of same brain showing distribution of labeled neurons. 5: Caudal section of same brain showing distribution of labeled neurons. 6: Frontal section of brain taken at the level of nucleus HVc from adult female canary killed 52 days after last of series of 28 injections of (3H)thymidine spaced 12 h apart. Each dot corresponds to a labeled neuron. Incubation period for autoradiography was 4 wk. Criterion for recognizing a labeled cell was 5 times background for all sections except 6, for which it was 10 times background. Using either criterion, there are many labeled neurons throughout forebrain (with exception of archistriatum) but very few, or none, outside forebrain. Sagittal view of brain (inset, lower left) shows level at which the 4 different sections were taken. A, archistriatum; APH, area parahippocampalis; Aq, aqueduct; Cb, cerebellum; FA, tractus frontoarchistriatalis; FLM, fasciculus longitudinalis medialis; HA, hyperstriatum accessorium; Hab, habenula; HD, hyperstriatum dorsalis; HP, hippocampus; HV, hyperstriatum ventralis; IM, nucleus isthmi pars magnocellularis; IPC, nucleus isthmi pars parvocellularis; LMD, lamina medullaris dorsalis; LPO, lobus parolfactorius; MLd, nucleus mesencephalicus lateralis pars dorsalis; N, neostriatum; NC, neostriatum caudalis; OM, tractus occipitomesencephalicus; PA, paleostriatum augmentatum; Pt, nucleus pretectalis; RA, nucleus robustus archistriatalis; SPM, nucleus spiriformis medialis; TPC, nucleus tegmenti pedunculopontinus pars compacta. Calibration bar, 1 mm.

Figure 13. Figure 13.

Histograms showing relative frequency with which various numbers of exposed silver grains occurred over nuclei of 100 labeled neurons (A), 100 labeled glia (B), and 100 labeled endothelial cells (C) taken from HVc and underlying neotriatum following systemic treatment with (3H)thymidine (see Fig. 12); this bird was killed 26 days after last (3H)thymidine injection. Brain sections were incubated for autoradiography for only 10 days and showed very low background labeling. As a result, criterion for accepting cell as labeled was only 3 exposed silver grains per nucleus, which corresponded to 10 times background label for area of similar size. Short incubation permitted counting all exposed silver grains, even over those nuclei that showed the heaviest concentration of label.



Figure 1.

Sound spectrograph of fragment of adult male canary song showing 3 different syllable types. Repetition of same syllable forms phrase. Syllables are composed of 1 or more elements, preceded by silent gap. Each element is represented by a fundamental frequency and 1 or more harmonics. Calibration bar, 0.5 s.

From Nottebohm and Nottebohm 104.


Figure 2.

Monthly changes in blood testosterone levels and song. A: blood testosterone (T) levels in monthly samples from a group of 6 adult male canaries. First sample was taken in May when birds were 12 mo; last sample was taken the following May when birds were 24 mo. Vertical bars, SE. B: mean size of song repertoires measured in numbers of syllables from recordings obtained from same birds as in A. Mean size of song repertoire shows 2 significant increases: during September/October and during March. C: mean number of new syllable types produced each month by same birds shows waves of new syllable addition with peaks in September and March. Net increase in total syllable numbers is smaller than addition of new syllables because some older syllables are lost. Periods of enhanced song learning seem to be preceded by drop in blood testosterone levels. (F. Nottebohm, M. E. Nottebohm, L. Crane, and J. C. Wingfield, unpublished observations).



Figure 3.

A: ventral view of larynx, trachea, and bronchi of adult canary. Vocal organ, or syrinx, has its own complement of muscles and is surrounded by interclavicular air sac (icas), which is part of respiratory system. Branch of hypoglossal nerve (XII), cervicalis descendens inferior (cds) or tracheosyringealis, innervates muscles of ipsilateral syringeal half. Recurrens branch of vagus nerve (RX) innervates nearby crop (not shown). bd, Bronchidesmus; ca, cerivcalis ascendens branch of XII nerve; gcs, cervical superior and gp, petrosum ganglia of IX nerve; h′, h″, hypoglossal and c, cervical roots of XII nerve; m st tr, sternotrachealis muscle; m tr I, tracheolateralis muscle. B: longitudinal section through syrinx. Left muscle mass is heavier than its right counterpart. Sound production is thought to result from periodic interruptions of airflow during expiration as internal tympaniform membrane (ti) oscillates in and out of bronchial lumen, possibly locked in step with local air turbulence. Bronchidesmal membrane anchors medial wall of bronchi to dorsal wall of interclavicular air sac. T, tympanum; b1, b2, and b3, bronchial half rings; LB, left bronchus; RB, right bronchus; le, labium externum; pe, pessulus; sl, semilunar membrane; M, intrinsic syringeal muscles.

From Nottebohm and Nottebohm 104.


Figure 4.

Two adult male canaries recorded while producing stable, adult song (trace A). Subsequently bird 1 had its right syringeal half denervated and bird 15 had its left syringeal half denervated (trace B). Song of bird 1 remained unaltered; postoperative song of bird 15 suffered loss of most syllable types, which were replaced by silent gaps, clicks, and other modified sounds.

From Nottebohm and Nottebohm 104.


Figure 5.

Schematic sagittal view of brain of adult male canary. Field L, highest forebrain auditory projection sends fibers that appose ventrally to nucleus hyperstriatum ventralis pars caudalis (HVc); HVc projects to nucleus robustus archistrialis (RA), which sends direct pathway to motoneurons of nucleus nervi hypoglossi (nXIIts) that innervate muscles of syrinx. All projections are ipsilateral. Distance from rostral to caudal end of brain, 13 mm. Cb, cerebellum.



Figure 6.

Two adult male canaries recorded while producing stable, adult song (trace A). Subsequently bird 54 had its right HVc lesioned and bird 97 had its left HVc lesioned. Both lesions were complete, resulting in elimination of HVc on one side (trace B). Song of bird 54 became unstable after the lesion, with intrusion of other independent sounds; syllable and phrase structure otherwise remained recognizable. Postoperative song of bird 97 lost virtually all of its preoperative syllable and phrase structure.

From Nottebohm et al. 106.


Figure 7.

Typical type IV RA cells of female (top) and male (bottom) canaries shown from behind, with reference to midline (M) and lateral (L) edge of brain. Same cells are then turned 90° and viewed from side, with reference to anterior (A) and posterior (P) end of brain. Dendritic trees were drawn with a motor‐driven microscope stage yoked to a computer, which allowed a complete threedimensional reconstruction of dendrites and their relative positions. Dotted lines, boundaries between contiguous 100 μm‐thick tissue sections used for reconstruction. Dorsal (D) and ventral (V) coordinates are same for 2 views of same cell. Male dendrites reach farther away from soma than do female dendrites.

From De Voogd and Nottebohm 31.


Figure 8.

Normal song development in male canaries, kept under photoperiod conditions of New York state, shown as horizontal progression from subsong (SS) to plastic song (PS) to full song (FS). FS is stable song that adult canaries sing during breeding season. At end of breeding season PS recurs. HVc volume grows during the time song is first acquired and shrinks to that of 3‐ to 4‐mo‐old canary in late summer after breeding season is over and song becomes plastic again. Vertical axis, volume of nucleus HVc ± 1 SD. Open circles, samples of 4 birds killed at age shown on horizontal axis; filled circles, samples of 9 and 12 birds killed at 12 and 17 mo, respectively; open diamonds, samples of 10, 9, and 8 birds killed at end of their 1st, 2nd, and 3rd breeding seasons, respectively.



Figure 9.

Sound spectrographs of 3 recordings from same bird. A: plastic song when bird was 4 mo old. B: plastic song produced in late summer (September) after end of its 1st breeding season. C: stable song during preceding May when bird was 12 mo old and in full reproductive condition. In A and B song syllables are repeated in wavering, unstable fashion; in C syllables are virtual carbon copies of each other. Calibration bar, 0.5 s.



Figure 10.

Camera lucida tracing of dendritic and axonal processes of HVc cell labeled with horseradish peroxidase andthymidine. Heavy lines, dendrites; light lines, axons. Boundaries of HVc: solid line, ventricle; broken line, fibrous lamina. Calibration bar, 100 μm. D and M, dorsal and medial reaches of the brain. [From Paton and Nottebohm 111. Copyright 1984 by the American Association for the Advancement of Science.]

3H


Figure 11.

Anatomy of HVc cell bodies labeled with horseradish peroxidase and (3H)thymidine. Seperate photographs were taken of same field but were focused first at level of cell itself (A and C) and then at level of exposed silver grains in layer of emulsion above cell (B and D). A and B, same cell; C and D, same cell. Calibration bar, 10 μm. (From Paton and Nottebohm 111. Copyright 1984 by the American Association for the Advancement of Science.)



Figure 12.

13: Distribution of labeled cells in same frontal brain section from an adult female canary killed 26 days after last of series of 28 injections of (3H)thymidine spaced 12 h apart. Each dot corresponds to a labeled cell; HVc is demarcated by broken line curving under lateral ventricle (V) of forebrain. 1: Labeled neurons. 2: Labeled glia. 3: Labeled endothelial cells. 4: Rostral section of same brain showing distribution of labeled neurons. 5: Caudal section of same brain showing distribution of labeled neurons. 6: Frontal section of brain taken at the level of nucleus HVc from adult female canary killed 52 days after last of series of 28 injections of (3H)thymidine spaced 12 h apart. Each dot corresponds to a labeled neuron. Incubation period for autoradiography was 4 wk. Criterion for recognizing a labeled cell was 5 times background for all sections except 6, for which it was 10 times background. Using either criterion, there are many labeled neurons throughout forebrain (with exception of archistriatum) but very few, or none, outside forebrain. Sagittal view of brain (inset, lower left) shows level at which the 4 different sections were taken. A, archistriatum; APH, area parahippocampalis; Aq, aqueduct; Cb, cerebellum; FA, tractus frontoarchistriatalis; FLM, fasciculus longitudinalis medialis; HA, hyperstriatum accessorium; Hab, habenula; HD, hyperstriatum dorsalis; HP, hippocampus; HV, hyperstriatum ventralis; IM, nucleus isthmi pars magnocellularis; IPC, nucleus isthmi pars parvocellularis; LMD, lamina medullaris dorsalis; LPO, lobus parolfactorius; MLd, nucleus mesencephalicus lateralis pars dorsalis; N, neostriatum; NC, neostriatum caudalis; OM, tractus occipitomesencephalicus; PA, paleostriatum augmentatum; Pt, nucleus pretectalis; RA, nucleus robustus archistriatalis; SPM, nucleus spiriformis medialis; TPC, nucleus tegmenti pedunculopontinus pars compacta. Calibration bar, 1 mm.



Figure 13.

Histograms showing relative frequency with which various numbers of exposed silver grains occurred over nuclei of 100 labeled neurons (A), 100 labeled glia (B), and 100 labeled endothelial cells (C) taken from HVc and underlying neotriatum following systemic treatment with (3H)thymidine (see Fig. 12); this bird was killed 26 days after last (3H)thymidine injection. Brain sections were incubated for autoradiography for only 10 days and showed very low background labeling. As a result, criterion for accepting cell as labeled was only 3 exposed silver grains per nucleus, which corresponded to 10 times background label for area of similar size. Short incubation permitted counting all exposed silver grains, even over those nuclei that showed the heaviest concentration of label.

References
 1. Altman, J. Autoradiographic investigation of cell proliferation in the brain of rats and cats. Anat. Rec. 145: 573–591, 1963.
 2. Altman, J. Postnatal growth and differentiation of the mammalian brain with implications for a morphological theory of memory. In: The Neurosciences: A Study Program, edited by G. C. Quarton, T. Melnechuk, and F. O. Schmitt. New York: Rockefeller Univ. Press, 1967, p. 723–743.
 3. Altman, J. DNA metabolism and cell proliferation. In: Handbook of Neurochemistry: Structural Neurochemistry, edited by A. Lajtha. New York: Plenum, 1969, vol. II, p. 137–182.
 4. Altman, J. Postnatal neurogenesis and the problem of neural plasticity. In: Developmental Neurobiology, edited by W. A. Himwich. Springfield, IL: Thomas, 1970, p. 192–237.
 5. Andrew, R. W., J. Mench, and C. Rainey. Right‐left asymmetry of response to visual stimuli in the domestic chick. In: Analysis of Visual Behavior, edited by D. J. Ingle, R. J. W. Mansfield, and M. A. Goodale. Cambridge, MA: MIT Press, 1974, p. 197–209.
 6. Arnold, A. P. Behavioral Effects of Androgen in Zebra Finches (Poephila guttata) and a Search for Its Site of Action. New York: Rockefeller Univ. Press, 1974. PhD thesis.
 7. Arnold, A. P. Quantitative analysis of sex differences in hormone accumulation in the zebra finch brain: methodological and theoretical issues. J. Comp. Neurol. 189: 421–436, 1980.
 8. Arnold, A. P., F. Nottebohm, and D. W. Pfaff. Hormone concentrating cells in vocal control and other areas of the brain of the zebra finch (Poephila guttata). J. Comp. Neurol. 165: 487–511, 1976.
 9. Arnold, A. P., and A. Saltiel. Sexual difference in pattern of hormone accumulation in the brain of a songbird. Science Wash. DC 205: 702–705, 1979.
 10. Ayoub, D. M., W. T. Greenough, and J. M. Juraska. Sex differences in dendritic structure in the preoptic area of the juvenile Macaque monkey brain. Science Wash. DC 219: 197–198, 1983.
 11. Baker, M. C., S. W. Bottjer, and A. P. Arnold. Sexual dimorphism and lack of seasonal changes in vocal control regions of the white‐crowned sparrow brain. Brain Res. 295: 85–89, 1984.
 12. Bayer, S. A. 3H‐thymidine‐radiographic studies of neurogenesis in the rat olfactory bulb. Exp. Brain Res. 50: 329–340, 1983.
 13. Bayer, S. A., J. W. Yackel, and P. S. Puri. Neurons in the rat dentate gyrus granular layer substantially increase during juvenile and adult life. Science Wash. DC 216: 890–892, 1982.
 14. Benton, A. L. Developmental dyslexia: neurological aspects. In: Advances in Neurology. Current Reviews of Higher Nervous System Dysfunction, edited by W. J. Friedlander. New York: Raven, 1975, vol. 7, p. 1–47.
 15. Bertram, B. The vocal behaviour of the Indian Hill Mynah, (Gracula religiosa). Anim. Behav. Monogr. 3: 79–192, 1970.
 16. Bleisch, W. V. Neuromuscular Functions in Androgen Sensitive Muscles: A Model for Synaptic Plasticity. New York: Rockefeller Univ. Press, 1982. PhD thesis.
 17. Bleisch, W., V. N. Luine, and F. Nottebohm. Modification of synapses in androgen‐sensitive muscle. I. Hormonal regulation of acetylcholine receptor number in the songbird syrinx. J. Neurosci. 4: 786–792, 1984.
 18. Boord, R. L. Ascending projections of the primary cochlear nuclei and nucleus laminaris in the pigeon. J. Comp. Neurol. 133: 523–530, 1968.
 19. Bottjer, S. W., and A. P. Arnold. Afferent neurons in the hypoglossal nerve of the zebra finch (Poephila guttata): localization with horseradish peroxidase. J. Comp. Neurol. 210: 190–197, 1982.
 20. Brain, L. Speech Disorders. London: Butterworths, 1965, p. 151, 154.
 21. Broca, P. Sur la faculté du langage articulé. Bull. Soc. Anthropol. 6: 377–393, 1865.
 22. Burd, G. D., and F. Nottebohm. Neurogenesis in adulthood. Ultrastructural characterization of synaptic terminals formed on newly generated neurons in a song control nucleus of the adult canary forebrain. J. Comp. Neurol. 240: 143–152, 1985.
 23. Canady, R. A., D. E. Kroodsma, and F. Nottebohm. Population differences in complexity of a learned skill are correlated with brain space involved. Proc. Natl. Acad. Sci. USA 81: 6232–6234, 1984.
 24. Cipolla‐Neto, J., G. Horn, and B. J. McCabe. Hemispheric asymmetry and imprinting: the effect of sequential lesions to the hyperstriatum ventrale. Exp. Brain Res. 48: 22–27, 1982.
 25. Cohen, J., and F. Nottebohm. Neural determinants of vocal behavior in birds that do not exhibit vocal learning. Soc. Neurosci. Abstr. 7: 270, 1981.
 26. Collias, N., and M. Joos. The spectrographic analysis of the sound signals of the domestic fowl. Behaviour 5: 175–189, 1953.
 27. De Lacoste‐Utamsing, C., and R. L. Holloway. Sexual dimorphism in the human corpus callosum. Science Wash. DC 216: 1431–1432, 1982.
 28. Denenberg, V. H., J. Garbanati, G. Sherman, D. A. Yutzey, and R. Kaplan. Infantile stimulation induces brain lateralization in rats. Science Wash. DC 201: 1150–1152, 1978.
 29. Devoogd, T. J., B. Nixdorf, and F. Nottebohm. Synaptogenesis and changes in synaptic morphology related to acquisition of a new behavior. Brain Res. 329: 304–308, 1985.
 30. Devoogd, T. J., and F. Nottebohm. Gonadal hormones induce dendritic growth in the adult avian brain. Science Wash. DC 214: 202–204, 1981.
 31. Devoogd, T. J., and F. Nottebohm. Sex differences in dendritic morphology of a song control nucleus in the canary: a quantitative Golgi study. J. Comp. Neurol. 196: 309–316, 1981.
 32. Diamond, M. C., G. A. Dowling, and R. E. Johnson. Morphological cerebral cortical asymmetry in male and female rats. Exp. Neurol. 201: 261–268, 1981.
 33. Diamond, M. C., R. E. Johnson, and C. A. Ingham. Morphological changes in the young, adult and aging rat cerebral cortex, hippocampus, and diencephalon. Behav. Biol. 14: 163–174, 1975.
 34. Geschwind, N., and W. Levitsky. Human brain: left‐right asymmetries in temporal speech region. Science Wash. DC 161: 186–187, 1968.
 35. Goldman, S. A., and F. Nottebohm. Neuronal production, migration, and differentiation in a vocal control nucleus of the adult female canary brain. Proc. Natl. Acad. Sci. USA 80: 2390–2394, 1983.
 36. Gorski, R. A., J. H. Gordon, J. E. Shryne, and A. M. Southam. Evidence for a morphological sex difference within the medial preoptic area of the rat brain. Brain Res. 148: 333–346, 1978.
 37. Graziadei, P. P. C., and G. A. Monti‐Graziadei. Neurogenesis and neuron regeneration in the olfactory system of mammals. I. Morphological aspects of differentiation and structural organization of the olfactory sensory neurons. J. Neurocytol. 8: 1–18, 1979.
 38. Greenewalt, C. H. Bird Song: Acoustics and Physiology. Washington, DC: Smithsonian, 1968.
 39. Greenough, W. T., C. S. Carter, C. Steerman, and T. J. Devoogd. Sex differences in dendritic patterns in hamster preoptic area. Brain Res. 126: 63–72, 1977.
 40. Gurney, M. E. Hormonal control of cell form and number in the zebra finch song system. J. Neurosci. 1: 658–673, 1981.
 41. Gurney, M. E., and M. Konishi. Hormone induced sexual differentiation of brain and behavior in zebra finches. Science Wash. DC 208: p. 1380–1383, 1980.
 42. Hamburger, V., and R. Levi‐Montalcini. Proliferation, differentiation and degeneration in the spinal ganglia of the chick embryo under normal and experimental conditions. J. Exp. Zool. 111: 457–502, 1949.
 43. Henrikson, C. K., and J. E. Vaughn. Fine structural relationships between neurites and radial glial processes in developing mouse spinal cord. J. Neurocytol. 3: 659–675, 1974.
 44. Immelmann, K. Song development in the zebra finch and other estrildid finches. In: Bird Vocalisations: Their Relation to Current Problems in Biology and Psychology, edited by R. A. Hinde. Cambridge, UK: Cambridge Univ. Press, 1969, p. 61–74.
 45. Johns, P. R. Growth of the adult goldfish eye. III. Source of the new retinal cells. J. Comp. Neurol. 176: 343–358, 1977.
 46. Johns, P. R., and R. D. Fernald. Genesis of rods in teleost fish retina. Nature Lond. 293: 141–142, 1981.
 47. Joos, M. Acoustic phonetics. Language 24, Suppl. 2: 1–136, 1948. (Language Monogr. 23.)
 48. Kaplan, M. S., and J. W. Hinds. Neurogenesis in the adult rat: electron miscroscopic analysis of light radioautographs. Science Wash. DC 197: 1092–1094, 1977.
 49. Karten, H. J. The organization of the ascending auditory pathway in the pigeon (Columba livia). I. Diencephalic projections of the inferior colliculus (nucleus mesencephali lateralis, pars dorsalis). Brain Res. 6: 409–427, 1967.
 50. Karten, H. The ascending auditory pathway in the pigeon (Columba livia). II. Telencephalic projections of the nucleus ovoidalis thalami. Brain Res. 11: 134–153, 1968.
 51. Karten, H. J., and W. Hodos. A Stereotaxic Atlas of the Brain of the Pigeon Columba livia. Baltimore, MD: Johns Hopkins Univ. Press, 1967.
 52. Katz, L. C., and M. E. Gurney. Auditory responses in the zebra finch's motor system for song. Brain Res. 221: 192–197, 1981.
 53. Kelley, D. B., and F. Nottebohm. Projections of a telencephalic auditory nucleus—field L—in the canary. J. Comp. Neurol. 183: 455–470, 1979.
 54. Konishi, M. The role of auditory feedback in the vocal behavior of the domestic fowl. Z. Tierpsychol. 20: 349–367, 1963.
 55. Konishi, M. The role of auditory feedback in the control of vocalization in the white‐crowned sparrow. Z. Tierpsychol. 22: 770–783, 1965.
 56. Korr, H. Proliferation of different cell types in the brain. Adv. Anat. Embryol. Cell Biol. 61: 1–72, 1980.
 57. Kroodsma, D. E. Reproductive development in a female songbird: differential stimulation by quality of male song. Science Wash. DC 192: 574–575, 1976.
 58. Kroodsma, D. E. A re‐evaluation of song development in the song sparrow. Anim. Behav. 25: 390–399, 1977.
 59. Kroodsma, D. E. Continuity and versatility in bird song: support for the monotony‐threshold hypothesis. Nature Lond. 274: 681–683, 1978.
 60. Kroodsma, D., and R. Pickert. Environmentally dependent sensitive periods for avian vocal learning. Nature Lond. 288: 477–479, 1980.
 61. Lashley, K. S. In search of the engram. In: Physiological Mechanisms in Animal Behaviour. New York: Academic, 1950, p. 454–482. (Symp. Soc. Exp. Biol. 4)
 62. Lemon, R. E. Nervous control of the syrinx in white‐throated sparrows (Zonotrichia albicollis). J. Zool. Lond. 171: 131–140, 1973.
 63. Leonard, R. B., R. E. Coggeshall, and W. D. Willis. A documentation of an age related increase in neuronal and axonal numbers in the stingray, Dasyatis sabina, Leseur. J. Comp. Neurol. 179: 13–21, 1978.
 64. Lieberburg, I., and F. Nottebohm. High‐affinity androgen binding proteins in syringeal tissues of songbirds. Gen. Comp. Endocrinol. 37: 286–293, 1979.
 65. Lippe, W., and E. W. Rubel. Development of the place principle: tonotopic organization. Science Wash. DC 219: 514–516, 1983.
 66. Luine, V., I. Lieberburg, F. Nottebohm, C. Harding, and B. McEwen. The avian syrinx: an androgen sensitive motor organ? Soc. Neurosci. Abstr. 4: 371, 1978.
 67. Luine, V., F. Nottebohm, C. Harding, and B. S. McEwen. Androgen affects cholinergic enzymes in songbird syringeal motor neurons and muscle. Brain Res. 192: 89–107, 1980.
 68. Manogue, K. R., and F. Nottebohm. Relation of medullary efferent nuclei to nerves supplying the vocal tract of the budgerigar (Melopsittacus undulatus). J. Comp. Neurol. 204: 384–391, 1982.
 69. Margoliash, D. Acoustic parameters underlying the responses of song‐specific neurons in the white‐crowned sparrow. J. Neurosci. 3: 1039–1057, 1983.
 70. Marler, P. Tonal quality of bird sounds. In: Bird Vocalisations: Their Relation to Current Problems in Biology and Psychology, edited by R. A. Hinde. Cambridge, UK: Cambridge Univ. Press, 1969, 5–18.
 71. Marler, P. A comparative approach to vocal learning: song development in white‐crowned sparrows. J. Comp. Physiol. Psychol. 71: 1–25, 1970.
 72. Marler, P. Birdsong and speech development: could there be parallels? Am. Sci. 58: 669–673, 1970.
 73. Marler, P., M. Kreith, and M. Tamura. Song development in hand raised Oregon juncos. Auk 79: 12–30, 1962.
 74. Marler, P., and S. Peters. Selective vocal learning in a sparrow. Science Wash. DC 198: 519–521, 1977.
 75. Marler, P., and S. Peters. Structural changes in song ontogeny in the swamp sparrow Melospiza georgiana. Auk 99: 446–458, 1982.
 76. Marler, P., and S. Peters. Subsong and plastic song: their role in the vocal learning process. In: Acoustic Communication in Birds: Song Learning and its Consequences, edited by D. E. Kroodsma and E. H. Miller. New York: Academic, 1982, vol. 2, p. 25–50.
 77. Marler, P., and V. Sherman. Song structure without auditory feedback: emendations of the auditory template hypothesis. J. Neurosci. 3: 517–531, 1983.
 78. Marler, P., and M. Tamura. Culturally transmitted patterns of vocal behavior in sparrows. Science Wash. DC 146: 1483–1486, 1964.
 79. Marler, P., and M. S. Waser. Role of auditory feedback in canary song development. J. Comp. Physiol. Psychol. 91: 8–16, 1977.
 80. McCasland, J. S., and M. Konishi. Interaction between auditory and motor activities in an avian song control nucleus. Proc. Natl. Acad. Sci. USA 78: 7815–7819, 1981.
 81. McEwen, B. S., L. C. Krey, and V. Luine. Steroid hormone action in the neuroendocrine system: when is the genome involved? In: The Hypothalamus, edited by S. Reichlin, R. J. Baldessarini, and J. B. Martin. New York: Raven, 1978, p. 255–268.
 82. McEwen, B. S., R. E. Zigmond, and J. L. Gerlach. Sites of steroid binding and action in the brain. In: Structure and Function of Nervous Tissue, edited by G. H. Bourne. New York: Academic, 1972, vol. 5, p. 205–291.
 83. McGlone, J. Sex differences in human brain asymmetry. A critical survey. Behav. Brain Sci. 3: 215–263, 1980.
 84. Metfessel, M. Roller canary song produced without learning from external sources. Science Wash. DC 81: 470, 1935.
 85. Mulligan, J. A. Singing behavior and its development in the song sparrow, Melospiza melodia. Univ. Calif. Publ. Zool. 81: 1–76, 1966.
 86. Nottebohm, F. Auditory experience and song development in the chaffinch, Fringilla coelebs. Univ. Calif. Publ. Zool. 110: 549–568, 1968.
 87. Nottebohm, F. The “critical period” for song learning. Univ. Calif. Publ. Zool. 111: 386–387, 1969.
 88. Nottebohm, F. Ontogeny of bird song. Science Wash. DC 167: 950–956, 1970.
 89. Nottebohm, F. Neural lateralization of vocal control in a passerine bird. I. Song. J. Exp. Zool. 177: 229–261, 1971.
 90. Nottebohm, F. Neural lateralization of vocal control in a passerine bird. II. Subsong, calls, and a theory of vocal learning. J. Exp. Zool. 179: 35–49, 1972.
 91. Nottebohm, F. Vocal behavior in birds. In: Avian Biology, edited by J. R. King and D. S. Farner. New York: Academic, 1975, vol. 5, p. 287–332.
 92. Nottebohm, F. Phonation in the orange‐winged Amazon parrot, Amazona amazonica J. Comp. Physiol. A Sens. Neural Behav. Physiol. 108: 157–170, 1976.
 93. Nottebohm, F. Asymmetries in neural control of vocalization in the canary. In: Lateralization in the Nervous System, edited by S. Harnad, R. W. Doty, L. Goldstein, J. Jaynes, and G. Krauthamer. New York: Academic, 1977, p. 23–44.
 94. Nottebohm, F. Testosterone triggers growth of brain vocal control nuclei in adult female canaries. Brain Res. 189: 429–436, 1980.
 95. Nottebohm, F. A brain for all seasons: cyclical anatomical changes in song control nuclei of the canary brain. Science Wash. DC 214: 1368–1370, 1981.
 96. Nottebohm, F., and A. P. Arnold. Sexual dimorphism in vocal control areas of the songbird brain. Science Wash. DC 194: 211–213, 1976.
 97. Nottebohm, F., and S. A. Goldman. Connectivity and kinetics of neurons born in adulthood. Soc. Neurosci. Abstr. 8: 140, 1982.
 98. Nottebohm, F., and S. Kasparian. Widespread labeling of avian forebrain neurons after systemic injections of 3H‐thymidine in adulthood. Soc. Neurosci. Abstr. 9: 380, 1983.
 99. Nottebohm, F., S. Kasparian, and C. Pandazis. Brain space for a learned task. Brain Res. 213: 99–109, 1981.
 100. Nottebohm, F., D. B. Kelley, and J. A. Paton. Connections of vocal control nuclei in the canary telencephalon. J. Comp. Neurol. 207: 344–357, 1982.
 101. Nottebohm, F., E. Manning, and M. E. Nottebohm. Reversal of hypoglossal dominance in canaries following syringeal denervation. J. Comp. Physiol. A Sens. Neural Behav. Physiol. 134: 227–240, 1979.
 102. Nottebohm, F., and M. Nottebohm. The parrots of Bush‐Bush. Anim. Kingdom LXXII: 18–23, 1969.
 103. Nottebohm, F., and M. Nottebohm. Vocalization and breeding behavior of surgically deafened ring doves, Streptopelia risoria. Anim. Behav. 19: 313–327, 1971.
 104. Nottebohm, F., and M. Nottebohm. Left hypoglossal dominance in the control of canary and white‐crowned sparrow song. J. Comp. Physiol. A Sens. Neural Behav. Physiol. 108: 171–192, 1976.
 105. Nottebohm, F., and M. E. Nottebohm. Relationship between song repertoire and age in the canary, Serinus canarius. Z. Tierpsychol. 46: 298–305, 1978.
 106. Nottebohm, F., T. M. Stokes, and C. M. Leonard. Central control of song in the canary, Serinus canarius. J. Comp. Neurol. 165: 457–486, 1976.
 107. Ojemann, G., and C. Mateer. Human language cortex: localization of memory, syntax, and sequential motor‐phoneme identification systems. Science Wash. DC 205: 1401–1403, 1979.
 108. Oppenheim, R. W., I. W. Chu‐Wang, and J. L. Maderdrut. Cell death of motoneurons in the chick embryo spinal cord. III. The differentiation of motoneurons prior to their induced degeneration following limb‐bud removal. J. Comp. Neurol. 177: 87–112, 1978.
 109. Paton, J. A., and K. Manogue. Bilateral interactions within the vocal control pathway of birds: two contrasting strategies. J. Comp. Neurol. 212: 329–335, 1982.
 110. Paton, J. A., K. R. Manogue, and F. Nottebohm. Bilateral organization of the vocal control pathway in the budgerigar (Melopsittacus undulatus). J. Neurosci. 1: 1279–1288, 1981.
 111. Paton, J. A., and F. Nottebohm. Neurons generated in adult brairi are recruited into functional circuits. Science Wash. DC 225: 1046–1048, 1984.
 112. Paton, J. A., B. O'Loughlin, and F. Nottebohm. Neurons born in a forebrain nucleus of adult canary are interneurons. J. Neurosci. 5: 3088–3093, 1985.
 113. Petersen, M. T., M. D. Beecher, S. R. Zoloth, D. B. Moody, and W. C. Stebbins. Neural lateralization of species‐specific vocalizations by Japanese macaques (Macaca fuscata). Science Wash. DC 202: 324–327, 1979.
 114. Pfaff, D. W. The neuroanatomy of sex hormone receptors in the vertebrate brain. In: Neuroendocrine Regulation of Fertility, edited by T. C. A. Kumar. Basel: Karger, 1976, p. 30–45.
 115. Potter, R. K., G. A. Kopp, and H. C. Green. Visible Speech. New York: Van Nostrand, 1947.
 116. Price, P. H. Developmental determinants of song structure in zebra finch song. J. Comp. Physiol. Psychol. 93: 260–277, 1979.
 117. Raisman, G., and P. M. Field. Sexual dimorphism in the preoptic area of the brain. Science Wash. DC 173: 731–733, 1971.
 118. Rakic, P. DNA synthesis and cell division in the adult primate brain. Ann. NY Acad. Sci. 457: 193–211, 1985.
 119. Raymond, P. A., and S. S. Easter. Postembryonic growth of the optic tectum in goldfish. I. Location of germinal cells and numbers of neurons produced. J. Neurosci. 3: 1077–1091, 1983.
 120. Rogers, L. J. Functional lateralisation in the chicken forebrain revealed by cycloheximide treatment. In: Acta XVII Congressus Internationalis Ornithologici, edited by R. Nohring. Berlin: Deutsche Ornithologen Gesellschaft, 1980, p. 653–659.
 121. Rogers, L. J., and J. M. Anson. Lateralisation of function in the chicken fore‐brain. Pharmacol. Biochem. Behav. 10: 679–686, 1979.
 122. Rubel, E. W., and B. M. Ryals. Development of the place principle: acoustic trauma. Science Wash. DC 219: 512–514, 1983.
 123. Rubini, J. R., E. P. Cronkite, V. P. Bond, and T. M. Fliedner. The metabolic fate of tritiated thymidine in man. J. Clin. Invest. 39: 909–919, 1960.
 124. Schiller, F. Paul Broca, Founder of French Anthropology, Explorer of the Brain. Berkeley: Univ. of California Press, 1979, p. 9.
 125. Seller, T. J. Unilateral nervous control of the syrinx in Java sparrows. J. Comp. Physiol. 129: 281–288, 1979.
 126. Thorpe, W. H. The learning of song patterns by birds, with special reference to the song of the chaffinch, Fringilla coelebs. J. Comp. Physiol. 100: 535–570, 1958.
 127. Thorpe, W. H., and P. M. Pilcher. The nature and characteristics of subsong. Br. Birds 51: 509–514, 1958.
 128. Von Woellwarth, C. Experimentelle Untersuchungen über den Situs inversus der Eingeweide und der Habenula des Zwischenhirns bei Amphibien. Wilhelm Roux' Arch. Entwick‐lungsmech. Org. 144: 178–256, 1950.
 129. Wolff, J. R., M. Rickmann, and B. M. Chronwall. Axoglial synapses and GABA‐accumulating glial cells in the embryonic neocortex of the rat. Cell Tissue Res. 201: 239–248, 1979.
 130. Zigmond, R. E., R. A. Detrick, and D. W. Pfaff. An autoradiographic study of the localization of androgen concentrating cells in the chaffinch. Brain Res. 182: 369–381, 1980.
 131. Zigmond, R. E., F. Nottebohm, and D. W. Pfaff. Androgen‐concentrating cells in the midbrain of a songbird. Science Wash. DC 179: 1005–1007, 1973.

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Fernando Nottebohm. Plasticity in Adult Avian Central Nervous System: Possible Relation Between Hormones, Learning, and Brain Repair. Compr Physiol 2011, Supplement 5: Handbook of Physiology, The Nervous System, Higher Functions of the Brain: 85-108. First published in print 1987. doi: 10.1002/cphy.cp010503