Sensory Schwann cells set perceptual thresholds for touch and selectively regulate mechanical nociception

That sensory neurons alone transduce mechanical stimuli was challenged by the discovery of nociceptive Schwann cells that can initiate pain. Consistent with the existence of inherently mechanosensitive sensory Schwann cells, we found that the mechanosensory function of almost all nociceptors, including those signaling fast pain, were critically dependent on sensory Schwann cells. Furthermore, in polymodal nociceptors, sensory Schwann cells signal mechanical, but not cold or heat pain. Terminal Schwann cells also surround mechanoreceptor nerve-endings within the Meissners corpuscle and in at hair follicle lanceolate endings that both signal vibrotactile touch. Within Meissners corpuscles, two molecularly and functionally distinct sensory Schwann cells positive for Sox10 and Sox2 differentially modulate rapidly adapting mechanoreceptor function. Using optogenetics we show that Meissners corpuscle Schwann cells are necessary for the perception of low threshold vibrotactile stimuli. These results show that sensory Schwann cells within diverse glio-neural mechanosensory end-organs are sensors for mechanical pain as well as necessary for touch perception. Thus, specialized sensory Schwann are central to the transduction of mechanical forces that underpin somatic sensation.