A finite-element model of mechanosensation by a Pacinian corpuscle cluster in human skin

The Pacinian corpuscle (PC) is the cutaneous mechanoreceptor responsible for sensation of high-frequency (20–1000 Hz) vibrations. PCs lie deep within the skin, often in multicorpuscle clusters with overlapping receptive fields. We developed a finite-element mechanical model of one or two PCs embedded within human skin, coupled to a multiphysics PC model to simulate action potentials elicited by each PC. A vibration was applied to the skin surface, and the resulting mechanical signal was analyzed using two metrics: the deformation amplitude ratio (({rho }_{mathrm{1S}} ), ({rho }_{mathrm{2S}} )) and the phase shift of the vibration (({delta }_{mathrm{S}1}^{mathrm{mech}} ), ({delta }_{mathrm{S}2}^{mathrm{mech}} )) between the stimulus and the PC. Our results showed that the amplitude attenuation and phase shift at a PC increased with distance from the stimulus to the PC. Differences in amplitude ((rho _{12} )) and phase shift (({delta }_{12}^{mathrm{mech}} )) between the two PCs in simulated clusters directly affected the interspike interval between the action potentials elicited by each PC (({delta }_{12}^{mathrm{spike}} )). While ({delta }_{12}^{mathrm{mech}} ) had a linear relationship with ({delta }_{12}^{mathrm{spike}} ), (rho _{12} )’s effect on ({delta }_{12}^{mathrm{spike}} ) was greater for lower values of (rho _{12} ). In our simulations, the separation between PCs and the distance of each PC from the stimulus location resulted in differences in amplitude and phase shift at each PC that caused ({delta }_{12}^{mathrm{spike}} ) to vary with PC location. Our results suggest that PCs within a cluster receive different mechanical stimuli which may enhance source localization of vibrotactile stimuli, drawing parallels to sound localization in binaural hearing.