Neural responses to songbird vocalizations in the nucleus taeniae of the amygdala in Bengalese finches

Abstract

Emotions are important psychological processes that induce adaptive behavior in response to communication signals. Many species of songbirds form complex social relationships and communicate with others through a large variety of vocal sounds. Thus, songbirds could be a good model to search for the neural basis of emotion especially in a context of communication. Anatomical studies have shown that the nucleus taeniae of the amygdala (TnA) in birds corresponds to the medial amygdala in mammals. While the amygdala is suggested to be involved in recognition of conspecific vocalizations in rats and bats, the function of the TnA still remains unclear. The present study aimed to explore auditory response properties of the songbird TnA by electrophysiology. We examined activity of the Bengalese finch TnA neurons during the presentations of conspecific and heterospecific vocalizations, as well as synthesized sound. We demonstrated for the first time that a population of TnA neurons exhibited selective auditory responses to songbird vocalizations. Our findings suggested involvement of the songbirds TnA for the recognition of communicative sounds. Further investigation into the TnA response properties should be fruitful in understanding the relationship between emotion and vocal signals in animals. [Work supported by JSPS KAKENHI Grant # 26240019.]