Seasonal female brain plasticity in processing social vs. sexual vocal signals.

While cerebral plasticity has been extensively studied and demonstrated - during ontogenetic development, few studies have considered adult plasticity in different social contexts using relevant social communication signals. Communication requires adaptability throughout the life of an individual, especially in species for which breeding periods (when intersexual signaling prevails) are interspersed with more 'social' (non-sexual) periods when intrasexual bonding prevails. In songbirds, structure or frequency of songs or song elements may convey different information depending on the season. This is the case in the European starling, where some song structures characterize social bonds between females while other song structures are more characteristic of male courtship. We hypothesized that the female perceptual system may have adapted to these changes in song structure and function according to season, and we tested for potential seasonal brain plasticity. Electrophysiological recordings from adult female starlings during playback of song elements with different functions showed clear seasonal (breeding/non-breeding) changes in neuronal responses in the primary auditory area. The proportion of responsive sites was higher in response to social (non-sexual) songs during the non-reproductive season, and higher in response to sexual songs during the reproductive season.