Multimodal integration of courtship signals in songbirds

• Applicant: Dr. Jennifer Kosubek-Langer
• Subject Area: Cognitive, Systems and Behavioural Neurobiology
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 471269724

The use of multimodal signaling to attract mates is taxonomically widespread and involves the use of more than one component in more than one sensory modality. In zebra finches, a model system for song learning and production, courtship involves multiple audio-visual signals including body postures, calls, song and dance. The neuronal basis of singing in male zebra finches is the ‘song control system’. It consists of several discrete song nuclei in interconnected pathways and facilitates song learning in juveniles and song production in adults. During courtship, audio-visual signals from female zebra finches elicit singing accompanied by a coordinated courtship dance in males. Female zebra finches, on the other hand, decide to mate upon the quality of the male’s performance. Interestingly, the simultaneous presentation of audio and visual courtship signals lead to stronger behavioral responses in both sexes. However, where and how multimodal courtship signals are associated in the brain is still unexplored. Furthermore, it has not yet been addressed how multimodal signals are ultimately forwarded onto pathways of the song control system and trigger courtship singing in males. The aims of the proposed project are i) identify brain regions in the zebra finch that associate multimodal courtship signals and ii) determine the signal flow between multimodal association areas and the song control system. A candidate brain region for the association of multimodal stimuli is the nidopallium caudolaterale (NCL), an endbrain structure that is considered a functional analogue of the prefrontal cortex in mammals. As an executive structure the NCL receives and processes inputs form all sensory modalities and sends projections to promotor areas. In pigeons and crows, the NCL is involved in many cognitive processes including learning and memory. Notably, individual neurons within the NCL of crows encode audio-visual associations across time and modality. To investigate if the NCL of zebra finches is also involved in the association of multimodal signals, this project aims to record neuronal population activity in the NCL during the presentation of uni- and multimodal behavioral relevant courtship stimuli. State-of-the-art Neuropixels probes will be used to simultaneously record in more than 380 individually selectable channels. To identify signal flow from multimodal association areas to the song system, the Neuropixels probe will simultaneously record neuronal activity in a) multimodal association areas, b) their efferent target regions, that have direct or indirect connections to the song system and c) in nuclei of the song system. Expected results will elucidate the neuronal structures underlying multimodal processing involved int the complex courtship behavior and mate choice in songbirds.

• DFG Programme: WBP Position