Mammalian touch catches up

- Selective genetic markers allow functional dissection of identified touch receptors.
- Piezo genes encode mechanically activated ion channels.
- Piezo2 is a principal component of mechanotransduction in mammalian touch receptors.
- Cellular and molecular mechanisms tune the mechanosensory function of touch receptors.

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.