Microglial refinement of spinal cord sensory circuitry regulates normal maturation of dynamic touch.

In the spinal cord dorsal horn, sensory circuits undergo remarkable postnatal reorganisation, including refinement of primary afferent A-fibres in the superficial layers, accompanied by decreased cutaneous sensitivity. Here we show a physiological role of microglia necessary for normal development of dorsal horn sensory circuits and tactile sensitivity. In the absence of microglial engulfment, superfluous A-fibre projections persist, leading to lifelong hypersensitivity to dynamic touch.