The hairs of our skin are mechanoreceptive: displacement of the hair is detected via sensory afferents in the hair follicle piloneural collar. In this complex structure, neurons, Schwann cells and keratinocytes are closely apposed, and interactions between these three cell types may influence differentiation and function of the piloneural collar. Here, David Owens and colleagues demonstrate that glutamate, which is known to mediate communication between neurons and Schwann cells in the central nervous system, has analogous activities in the periphery (). Signalling between VGLUT2-expressing neurons and NMDA receptor-expressing Schwann cells directs both formation and maintenance of the piloneural collar in mice. In conditional VGLUT2 mutants, the Schwann cells are disorganised and overall collar structure is severely disrupted. Moreover, treating the skin of adult mice with an NMDA receptor antagonist impairs touch-evoked responses, demonstrating defects in piloneural collar activity. Thus, continuous glutamate signalling between neurons and Schwann cells in the piloneural collar of the skin is essential for the integrity and function of this elaborate mechanosensory structure.
