Modulation of Peripheral and Central Auditory Processing by Estrogens in Birds

Abstract

A growing body of literature points to the importance of estrogens in the development, maintenance, modulation, and protection of vertebrate audition. Birds, with their long history in endocrinological research, and their reliance on vocal communication for reproductive and social interactions, have proven to be particularly fruitful for such studies. This chapter summarizes current knowledge about the role of estrogens in avian auditory function, with a special emphasis on songbirds. Abundant evidence supports the notion that both peripheral and brain- derived estrogens modulate sound-evoked activity throughout the songbird auditory neuraxis. Estrogens infl uence audition at multiple timescales, ranging from sea- sonal variation to acute minute-by-minute variation. Moreover, estrogen actions occur in both males and females, indicating that estrogens are principal regulators of auditory function. Collectively, these fi ndings highlight the need for new avenues of inquiry. Future areas of investigation include the intracellular mechanisms trig- gered by non-classical estrogenic pathways and a deeper exploration of the effects of estrogens on sensory encoding and decoding.