Encoding social preference by interhemispheric neurons in the Insula

The Insula is a multisensory relay that participates in socio-emotional processing through multiple projections to sensory, cognitive, emotional, and motivational regions. Interestingly, the Insula interhemispheric projection to the contralateral Insula is a strong but understudied projection. Using cutting-edge neuroanatomy, ex vivo and in vivo electrophysiology associated with specific circuit manipulation, we unraveled the nature and role of Insula interhemispheric communication in social and anxiety processing in mice. In this study, we 1) characterized the anatomical and molecular profile of the interhemispheric neurons of the Insula, 2) highlighted that stimulation of this neuronal subpopulation triggers excitation in the Insula interhemispheric circuit 3) uncovered their engagement in social processing. In conclusion, this study demonstrates that interhemispheric neurons of the Insula constitute a unique class of Insula neurons and proposes new meaningful insights into the neuronal mechanisms underlying social behavior.