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 exchange of social cues between individuals enhances the growth of the song system during the breeding season. 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. We will determine whether the social enhancement of the seasonal growth of the song nuclei is mediated by auditory stimuli. We will examine whether social stimulation from other birds enhances the growth of the song nuclei by increasing the recruitment and/or survival of newly generated neurons in the adult bird's song system. To test the hypothesis that maintenance of seasonally grown song nuclei depends on innervation from afferent nuclei, we will lesion nucleus HVc unilaterally in canaries that have been on breeding photoperiods for one month and compare the morphology of the afferent nuclei RA and Area X ipsilateral and contralateral to the lesion. The hypothesis that seasonal growth of the song nuclei is regulated by estrogenic metabolites of testosterone will be tested by measuring the morphology of song nuclei, song behavior, and plasma hormone levels in wild song sparrows implanted in early Fall with different steroids. We will use operant conditioning techniques to test the hypothesis that seasonal changes in song perception are functionally related to seasonal plasticity of the song system. The results of the proposed studies will increase our understanding of steroid hormonal and social 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 #
5R01MH053032-07
Application #
6392116
Study Section
Special Emphasis Panel (ZRG1-IFCN-2 (01))
Project Start
1995-04-01
Project End
2005-03-31
Budget Start
2001-04-01
Budget End
2002-03-31
Support Year
7
Fiscal Year
2001
Total Cost
$317,185
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

Showing the most recent 10 out of 57 publications