Gambel's white-crowned sparrows are songbirds that breed seasonally. Like many other songbirds, they exhibit dramatic seasonal differences in song behavior, and in the morphology and physiology of the neural circuit underlying song production. Androgenic and estrogenic steroid sex hormones mediate these seasonal changes. While much work has focused on the hormonal mechanisms underlying seasonal plasticity in songbird vocal production, comparatively little work has investigated seasonal and hormonal effects on songbird auditory processing. Preliminary auditory brainstem response (ABR) data demonstrate that breeding condition white-crowned sparrows have significantly increased thresholds and latencies than non-breeding birds;however, a detailed assessment of these effects remains to be accomplished. The focus of my research is to use white-crowned sparrows as a model for further characterizing seasonal and hormonal influences on auditory function. Using extracellular single-unit recording methods, Specific Aim 1 will determine where in the auditory system seasonal differences originate.
Specific Aim 2 will identify which hormone receptors mediate these changes by utilizing a variety of hormone treatments, immunohistochemistry and ABR recording. Finally, Specific Aim 3 will determine if seasonal differences observed in the peripheral/brainstem auditory system are conserved in forebrain processing regions.

Public Health Relevance

A growing body of literature links human hearing and steroid hormones, but the nature and mechanism of these interactions remain unknown. To better understand the extrinsic and intrinsic conditions that regulate the sensitivity and selectivity of hearing as related to communication signals, I have chosen to study the peripheral and central auditory system of songbirds. The research I propose here will use white-crowned sparrows as a model to better understand the hormonal mechanisms that influence and underlie normal hearing function, and is thus directly relevant to the mission of NIDCD.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
5F31DC010938-03
Application #
8274668
Study Section
Communication Disorders Review Committee (CDRC)
Program Officer
Sklare, Dan
Project Start
2010-06-16
Project End
2013-02-28
Budget Start
2012-06-16
Budget End
2013-02-28
Support Year
3
Fiscal Year
2012
Total Cost
$28,589
Indirect Cost
Name
University of Washington
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
605799469
City
Seattle
State
WA
Country
United States
Zip Code
98195
Caras, Melissa L (2013) Estrogenic modulation of auditory processing: a vertebrate comparison. Front Neuroendocrinol 34:285-99