Neural Activity During Call Production in the Female Zebra Finch Homolog of the Male Forebrain Song System

TL;DR

Female zebra finches use a brain region similar to the male song system for call-based communication, even though they cannot sing.

Contribution

This study shows that the RA nucleus in female zebra finches is functionally involved in call production, not just in males.

Findings

RA neurons in females show premotor activity during stack and tet call production.

RA units are active when females respond to or initiate a male's call.

Spontaneous RA activity in females is rare and not linked to vocal output.

Abstract

Female zebra finches (
Taeniopygia guttata
) are unable to sing because of the vestigial development of forebrain song control areas such as the RA (nucleus robustus archistriatalis), a premotor nucleus of the song control pathway. In male zebra finches, RA is also involved in call‐based vocal communication in addition to song control. Here, we monitored the activity of RA neurons during vocal communication in freely behaving females using a miniaturized telemetric recording device combined with telemetric audio recording. Neurons in the RA region showed premotor activity associated with stack and tet calls, two innate short‐range social calls produced by both sexes. RA units were active when females called to respond to a male partner's call or to initiate a partner's call. However, spontaneous, regularly firing units, typical of male RA, were very rare in females or, when found, showed no association with vocal output. Despite the small number of adult female RA neurons, these neurons are not functionless, but are involved in call‐based communication.

Although female zebra finches do not learn vocalizations, they possess brain structures analogous to those of males that use these structures to learn a large part of their vocal output, such as song. We wirelessly recorded neural signals from one of these brain areas, premotor nucleus RA, simultaneously with the vocal output from freely behaving females. These recordings show that females, like males, do use their “song system” during the exchange of stack and tet calls with their partners.

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