SOCKMAN, K.W.*; GENTNER, T.Q.; BALL, G.F.: Experience modulates forebrain response to mate choice cues

Within minutes of a behaviorally relevant stimulus, the brain responds with a pulse of immediate-early-gene (IEG) transcription that alters processes in long-term memory formation. This genomic response can vary with stimulus type, but its sensitivity to nuances in social experience is unknown. In many bird species, females choose mates based on inter-male variation in song. Female starlings (Sturnus vulgaris) prefer long- over short-bout songs and show higher induction of the IEG ZENK in the auditory forebrain when exposed to long- than to short-bout songs. We held female starlings on an 8 hr light-16 hr dark (8L 16D) photoperiod and then tested whether recent experience modulates this bout-length response bias. In three successive sessions, we transferred females to 11L 13D and exposed them to one week of either short- or long-bout songs (experience) followed by 30 min of either short- or long-bout songs (stimulus), 60 min after which we collected their brains. We quantified ZENK protein by immunocytochemistry in the caudo-medial hyperstriatum ventrale and the caudo-medial neostriatum, areas involved in song processing specifically. ZENK induction in both areas increased with session number, suggesting that exposure to a short photophase sensitizes females to song. ZENK induction in both areas was higher in females exposed to long- than in those exposed to short-bout stimulus. However, short-bout experience attenuated this response bias, whereas long-bout experience amplified it. This experience-based genomic plasticity may underlie a mechanism for optimizing mate-choice criteria amidst locally variable distributions of male secondary sex characteristics. Whether this genomic plasticity gives rise to behavioral plasticity awaits further study.