Differential effects of vocalization type, singer and listener on ZENK immediate early gene response in black-capped chickadees (Poecile atricapillus).

Here we examined immediate early gene (ZENK) induction to vocalizations in the ascending auditory pathway of black-capped chickadees (Poecile atricapillus) to assess the impact that the sex of the producer and perceiver has on ZENK induction. We manipulated the playback by both the vocal type (song/call) and sex of producer (male/female), and then presented these stimuli classes to either male or female black-capped chickadees. Neural response to the stimulus was quantified by the amount of protein of the IEG ZENK (also known as zif-268, egr-1, ngf-Ia and krox-24) in the caudal medial nidopallium (NCM) and caudomedial mesopallium (CMM). Overall, there was more ZENK induction in CMM and the dorsal parts of the caudal medial nidopallium (NCMd) than in the ventral parts of the caudal medial nidopallium (NCMv) and males had more ZENK induction than females. CMM had the most complex responding of ZENK induction to stimuli such that vocalization type, sex of producer, and sex of perceiver all affected ZENK induction. The silence controls had the least ZENK induction compared to any other group.