Touch is an intrinsically active sense. As humans primarily use our hands to actively gather tactile information, mice use their whiskers to explore their environment. Leveraging the mouse whisker system as a model for active touch, we focused on understanding the mechanical sensitivity of a type of touch receptor called the Merkel cell-neurite complex. Employing optogenetics, electrophysiology and mechanical models, we found that these touch receptor neurons reliably encode features of both object touch and whisker position.
This remarkable mechanical sensitivity supports the Merkel cell-neurite complex’s hypothesized role in perception of object shape. Furthermore, this work adds evidence that we should model touch and proprioception, the sense of body position, within a unified mechanical framework. These models could be particularly important for our basic understanding of touch perception, as well as engineering touch and proprioceptive feedback in prosthetics and robotics.