The impact of C-Tactile Low threshold mechanoreceptors on affective touch and social interactions in mice.

Abstract

Affective touch is necessary for proper neurodevelopment and sociability. However, it is still unclear how the neurons innervating the skin detect affective and social behaviours. To clarify this matter, we targeted a specific population of somatosensory neurons in mice, named C-low threshold mechanoreceptors (C-LTMRs), that appears particularly well suited physiologically and anatomically to perceive affective and social touch but whose contribution to these processes has not yet been resolved. Our observations revealed that C-LTMRs functional deficiency from birth induced social isolation and reduced tactile interactions in adults. Conversely, transient increase in C-LTMRs excitability in adults using chemogenetics was rewarding, temporally promoted touch seeking behaviours and thus had pro-social effects on group dynamics. This work provides the first empirical evidence that specific peripheral inputs alone can drive complex social behaviour, demonstrating the existence of a specialised neuronal circuit originating from the skin wired to promote interaction with other individuals.