Symmetry and adaptation of touch responses

Abstract:
Our tactile perceptions arise from diverse receptors that innervate our skin. Mechanical stimulations deform the tissue where touch receptor neurons (TRNs) are embedded and drive their activity. The understanding of biophysical mechanisms that gate touch receptor neurons is limited and benefits from the investigation of simpler organisms, such as the worm C. elegans. Like for human Pacini cells, TRNs of C. elegans show rapid adaptation to constant stimuli and symmetric responses to the onset and offset of stimuli. I shall present a model for the mechanical gating of TRNs, which is based on the elasticity of thin shells. The model provides a general mechanism that explains both adaptation and symmetry of the touch response, and its predictions are tested for a diverse range of experimental mechanical stimulations. Finally, I shall discuss the combination of modeling and numerical simulations of geometrically nonlinear elasticity that we are using to probe the mechanics of the worm’s body in the touch sensation and the fine structure of the gating mechanism.