Mammalian touch catches up

Abstract

An assortment of touch receptors innervate the skin and encode different tactile features of the environment. Compared with invertebrate touch and other sensory systems, our understanding of the molecular and cellular underpinnings of mammalian touch lags behind. Two recent breakthroughs have accelerated progress. First, an arsenal of cell-type-specific molecular markers allowed the functional and anatomical properties of sensory neurons to be matched, thereby unraveling a cellular code for touch. Such markers have also revealed key roles of non-neuronal cell types, such as Merkel cells and keratinocytes, in touch reception. Second, the discovery of Piezo genes as a new family of mechanically activated channels has fueled the discovery of molecular mechanisms that mediate and mechanotransduction in mammalian touch receptors.

The Cellular and Mechanical Basis for Response Characteristics of Identified Primary Afferents in the Rat Vibrissal System

“…Biomechanical modeling suggests that all afferents are broadly tuned but may differ in sensitivity to particular mechanical signals. Our results complement recent genetic approaches that have focused on the molecular mechanisms underlying tactile sensing [27][28][29] and offer a detailed quantification of the sensing machinery underlying vibrissal somatosensation: the stimulus is precisely controlled; mechanics and geometry are quantified; and morphology and anatomy of recorded afferents are verified.…”

The Role of PIEZO2 in Human Mechanosensation

“…5,6 PIEZO2 is expressed in subsets of somatosensory neurons 4,7 and Merkel cells. 8,9 In mice, PIEZO2 has been shown to be essential for a variety of mechanosensory responses, including aspects of light touch 7–10 and proprioception.…”

Evolutionary Specialization of Tactile Perception in Vertebrates

“…Most of our knowledge of the physiology and molecular basis of mechanosensation comes from studies with rodents, worms, and flies, and is extensively covered in recent reviews (3,32,38,41,59,72,78,80,82,84). Here, we will focus on adaptations to tactile perception in acutely mechanosensitive vertebrates, which are not considered standard model organisms.…”