TitleEstrogenic modulation of auditory processing in female songbirds
NameYoder, Kathleen Marie (author), Vicario, David (internal member), Kusnecov, Alexander (internal member), West, Mark (internal member), Rutgers University, Graduate School - New Brunswick,
DescriptionIn songbirds, male song is learned and is thought to be sexually selected for as a function of female mate choice. In this view, females must choose a conspecific mate whose song provides an honest signal of his quality. Male zebra finches copy an adult tutor’s song during development, and a memory for this tutor song is stored in the brain auditory processing area NCM. Female zebra finches do not copy, but they do show a behavioral preference in adulthood for the tutor song that they heard during development. Surprisingly, female NCM does not appear to have a memory for the tutor-song like that in males. We hypothesized that the expression of this memory in female NCM can be modulated by gonadal hormones, specifically that physiological estrogen levels in breeding females may influence sexual behavior by inducing changes in NCM that allow the previously formed tutor-song memory to be expressed, enable conspecific sounds to be discriminated from less relevant sounds, and facilitate acquisition of new auditory memories - all processes which may contribute to successful mate choice and reproduction. We tested these hypotheses by rearing females (n=26) in a controlled environment and exposing them to an artificial song-tutor during the sensitive period. In adulthood, we recorded their electrophysiological responses to tutor-song playback during estrogen (n=10), anti-estrogen (n=8) or vehicle (n=8) treatment. We also tested the same animals for conspecific vs. heterospecific song discrimination and the acquisition of memories for recently heard songs. Our results did not show an effect of hormonal manipulations on the expression of the tutor-song memory and thus did not support our primary hypothesis. However, anti-estrogen treatment degraded conspecific song discrimination and the acquisition of a memory for recently heard songs, suggesting that these processes require normal estrogen levels for their expression. Our results are consistent with an important role for estrogen in auditory processing and memory acquisition, consistent with studies in other animal systems. Future work will address the mechanisms by which estrogen modulates these effects.
NoteIncludes bibliographical references (p. 47-50)
Noteby Kathleen Marie Yoder
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work