A fundamental feature of nervous systems is that they provide plasticity of structure and function which allows animals to adapt to changes in their environment. We are only beginning to understand the underlying mechanisms, the limitations, and the behavioral consequences, such as learning, of naturally occurring plasticity in the brain. The song control system in the avian brain provides excellent opportunities for addressing such basic issues of behavioral neuroscience. Seasonal changes of environmental factors, such as photoperiod, have a profound effect on birds and most other animals. In songbirds seasonal changes in photoperiod elicit changes in circulating concentrations of gonadal steroid hormones, which in turn cause changes in song behavior and in morphological and physiological attributes of the neuroendocrine system that controls song. The goal of this proposal is to use a comparative approach to explore the proximate mechanisms and behavioral functions of seasonal plasticity in the avian song control system. The time course of changes in the morphology of song nuclei following changes in seasonal photoperiod will be examined in male canaries. Autoradiographic techniques will be used to determine whether seasonal changes in the cellular accumulation of gonadal steroid hormones underlie changes in the morphology of song nuclei in canaries. To test the hypothesis that seasonal changes in song nuclei depend on innervation from afferent nuclei, we will lesion nucleus HVC unilaterally in canaries and compare the morphology of the efferent nuclei RA and Area X ipsilateral and contralateral to the lesion following exposure to a breeding photoperiod. Song behavior, hormone concentrations, and song nuclei will be measured in wild Nuttal's white-crowned sparrows during and after the breeding season to test for seasonal changes in this subspecies. Using wild male song sparrows, song behavior, hormone concentrations, and song nuclei will be measured at four different times of year to test the hypothesis that seasonal changes in song production correlate with seasonal plasticity of the song nuclei. The results of the proposed studies will increase our understanding of steroid hormonal influences on the nervous system, and of the relationship between plasticity in the adult brain and learning.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Research Project (R01)
Project #
5R01MH053032-05
Application #
2890635
Study Section
Psychobiology, Behavior, and Neuroscience Review Committee (PBN)
Project Start
1995-04-01
Project End
2000-03-31
Budget Start
1999-04-01
Budget End
2000-03-31
Support Year
5
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Washington
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195
Larson, Tracy A; Thatra, Nivretta M; Hou, Daren et al. (2018) Seasonal changes in neuronal turnover in a forebrain nucleus in adult songbirds. J Comp Neurol :
Cohen, Rachel E; Macedo-Lima, Matheus; Miller, Kimberly E et al. (2016) Adult Neurogenesis Leads to the Functional Reconstruction of a Telencephalic Neural Circuit. J Neurosci 36:8947-56
Brenowitz, Eliot A; Remage-Healey, Luke (2016) It takes a seasoned bird to be a good listener: communication between the sexes. Curr Opin Neurobiol 38:12-7
Larson, Tracy A; Lent, Karin L; Bammler, Theo K et al. (2015) Network analysis of microRNA and mRNA seasonal dynamics in a highly plastic sensorimotor neural circuit. BMC Genomics 16:905
Brenowitz, Eliot A; Larson, Tracy A (2015) Neurogenesis in the adult avian song-control system. Cold Spring Harb Perspect Biol 7:
Caras, Melissa L; Sen, Kamal; Rubel, Edwin W et al. (2015) Seasonal plasticity of precise spike timing in the avian auditory system. J Neurosci 35:3431-45
Brenowitz, Eliot A (2015) Transsynaptic trophic effects of steroid hormones in an avian model of adult brain plasticity. Front Neuroendocrinol 37:119-28
Small, Thomas W; Brenowitz, Eliot A; Wojtenek, Winfried et al. (2015) Testosterone Mediates Seasonal Growth of the Song Control Nuclei in a Tropical Bird. Brain Behav Evol 86:110-21
Brenowitz, Eliot A; Zakon, Harold H (2015) Emerging from the bottleneck: benefits of the comparative approach to modern neuroscience. Trends Neurosci 38:273-8
Larson, Tracy A; Thatra, Nivretta M; Lee, Brian H et al. (2014) Reactive neurogenesis in response to naturally occurring apoptosis in an adult brain. J Neurosci 34:13066-76

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