The Human Cutaneous Sensory Corpuscles: An Update

Abstract

Sensory corpuscles of human skin are terminals of primary mechanoreceptive neurons associated with non-neuronal cells that function as low-threshold mechanoreceptors. Structurally, they consist of an extreme tip of a mechanosensory axon and nonmyelinating peripheral glial cells variably arranged according to the morphotype of the sensory corpuscle, all covered for connective cells of endoneurial and/or perineurial origin. Although the pathologies of sensitive corpuscles are scarce and almost never severe, adequate knowledge of the structure and immunohistochemical profile of these formations is essential for dermatologists and pathologists. In fact, since sensory corpuscles and nerves share a basic structure and protein composition, a cutaneous biopsy may be a complementary method for the analysis of nerve involvement in peripheral neuropathies, systemic diseases, and several pathologies of the central nervous system. Thus, a biopsy of cutaneous sensory corpuscles can provide information for the diagnosis, evolution, and effectiveness of treatments of some pathologies in which they are involved. Here, we updated and summarized the current knowledge about the immunohistochemistry of human sensory corpuscles with the aim to provide information to dermatologists and skin pathologists.

The Mechanoreceptor’s Role in Plantar Skin Changes in Individuals with Diabetes Mellitus

“…VPTs were measured in a prone position at two different frequencies (30 and 200 Hz) and anatomical locations (first metatarsal head (MET I) and heel) of the left or right foot. These two frequencies are considered ideal for measuring RAI and RAII [11,12]. The foot, frequency and anatomical location tested for each subject were randomized.…”

“…According to Jablonski, the sense of touch is the oldest sense, often referred to as "the mother of the senses" [9]. A large number of receptors, so-called low-threshold mechanoreceptors (LTMRs), ensure that humans can perceive a wide variety of sensations [10][11][12]. According to their functions, LTMRs can be divided into rapidly (RA) and slowly adapting (SA) type I and type II mechanoreceptors, with fast conduction velocities due to Aß sensory neurons [10][11][12].…”

“…A large number of receptors, so-called low-threshold mechanoreceptors (LTMRs), ensure that humans can perceive a wide variety of sensations [10][11][12]. According to their functions, LTMRs can be divided into rapidly (RA) and slowly adapting (SA) type I and type II mechanoreceptors, with fast conduction velocities due to Aß sensory neurons [10][11][12]. In the glabrous skin, the mechanosensory end organs correspond to the following four types: Merkel cells (SAI), Ruffini corpuscles (SAII), Meissner corpuscles (RAI) and Pacinian corpuscles (RAII).…”

“…RAI are tuned to low-frequency vibrations . RA II primarily response to high-frequency vibrations within a range of 20-1500 Hz, with optimal activation around 200 Hz [11,12].…”

Charging Up the Periphery: Glial Ionic Regulation in Sensory Perception

“…These structures include Meissner’s corpuscles (which sense pressure), Pacinian corpuscles (which sense vibration), and Ruffini’s corpuscles (which sense skin stretch). Both physiological and biophysical studies suggest that this lamellar encapsulation contributes to somatosensory perception ( Cobo et al, 2021 ).…”