Slow touch in non-human species: translational research into the C-tactile (CT) afferent system

Slowly conducting, low threshold mechanoreceptive afferents, with distinctive physiological properties, are present in humans (C-tactile afferents, CTs) and non-human species (C-low threshold mechanoreceptors, C-LTMs). In mice, gene expression profiles reveal abundant (TH+), and sparse (MRGPRB4+) C-LTM populations. Genetic manipulation of CLTMs allows specific investigations into how changing C-LTM activity impacts on affective behavior. Activation induces positive affect and disruption reduces social behavior and increases negative affect, adding to the CT affective touch hypothesis. Future genetic studies will allow analysis of the correspondence between species, but CTs likely predominantly correspond to TH+ C-LTMs and MRGPRB4+ CLTMs may be a subpopulation. These studies will help elucidate the roles and functions of the CT afferent system and identify ways to specifically modify tactile affect.

Automated summary

This study explores the presence of slow conducting, low threshold mechanoreceptive afferents in humans and non-human species, as well as the impact of genetic manipulation on affective behavior. Activation of C-LTMs induces positive affect, while disruption reduces social behavior and increases negative affect. Future research will further elucidate the roles and functions of the CT afferent system.