Multiscale Mechanical Model of the Pacinian Corpuscle Shows Depth and Anisotropy Contribute to the Receptor’s Characteristic Response to Indentation

Abstract

Cutaneous mechanoreceptors transduce different tactile stimuli into neural signals that produce distinct sensations of touch. The Pacinian corpuscle (PC), a cutaneous mechanoreceptor located deep within the dermis of the skin, detects high frequency vibrations that occur within its large receptive field. The PC is comprised of lamellae that surround the nerve fiber at its core. We hypothesized that a layered, anisotropic structure, embedded deep within the skin, would produce the nonlinear strain transmission and low spatial sensitivity characteristic of the PC. A multiscale finite-element model was used to model the equilibrium response of the PC to indentation. The first simulation considered an isolated PC with fiber networks aligned with the PC’s surface. The PC was subjected to a 10 μm indentation by a 250 μm diameter indenter. The multiscale model captured the nonlinear strain transmission through the PC, predicting decreased compressive strain with proximity to the receptor’s core, as seen experimentally by others. The second set of simulations considered a single PC embedded epidermally (shallow) or dermally (deep) to model the PC’s location within the skin. The embedded models were subjected to 10 μm indentations at a series of locations on the surface of the skin. Strain along the long axis of the PC was calculated after indentation to simulate stretch along the nerve fiber at the center of the PC. Receptive fields for the epidermis and dermis models were constructed by mapping the long-axis strain after indentation at each point on the surface of the skin mesh. The dermis model resulted in a larger receptive field, as the calculated strain showed less indenter location dependence than in the epidermis model.

Progressive recruitment of distal MEC-4 channels determines touch response strength in C. elegans

“…In many cases, the complexity of skin has made it difficult to understand the strain field. Although useful models have been created (Lesniak and Gerling, 2009;Quindlen et al, 2015;Quindlen-Hotek and Barocas, 2018;Sanzeni et al, 2019), few studies build on these models to generate an integrated understanding of how mechanical strain is detected by mechanosensitive proteins, including ion channels, distributed within somatosensory neurons.…”

Progressive recruitment of distal MEC-4 channels determines touch response strength inC. elegans

“…In many cases the complexity of skin has made it difficult to understand the strain field. While useful models have been created (Lesniak and Gerling, 2009;Quindlen et al, 2015;Quindlen-Hotek and Barocas, 2018;Sanzeni et al, 2018), few studies build on these models to generate an integrated understanding of how mechanical strain is detected by mechanosensitive proteins, including ion channels, distributed within somatosensory neurons.…”

A new type of somatosensory organ in the nasolabial skin of the dog

“…The mechanoreceptive function of the cutaneous receptors has been established in a number of investigations (Biemesderfer, Munger, Binck, & Dubner, 1978; Chambers, Andres, Von Düring, & Iggo, 1972; Iggo & Andres, 1982; Iggo & Muir, 1969; Iggo & Ogawa, 1977; Quindien, Lai, & Barocas, 2015). For this function, it is important that the connective tissue and collagen fibers are part of the capsule and linked to the surrounding connective tissue.…”