Abstract
The sense of light touch is indispensable for environmental exploration,social interaction, and skilled tasks but the underlying mechanisms are largely unknown in mammals. Tactile dysfunction such as neuropathic pain produce allodynia which is grievous pain generated by light touch. This intra ctable phenomenon is induced by neural sensitization after the damage to nervous system. Along with the nervous system mechanisms, mechano transdcution in the tactile end organs play a crucial role to form mechanical allodynia. Thus, the elucidation of touch mystery is great expected matter to develop the effective treatment against mechanical allodynia. Merkel discs are one of the tactile special end organs thought as putative mechanoreceptors in the skins and can make sophisticated discrimination. We performed in situ patch–clamp recording from Merkel cells which compose Merkel discs in company with Aβ–afferent nerve endings. As a result, Merkel cells showed transduction of tactile stimuli via “Piezo2” channels and encode tactile signals in the form of Ca2+ action potentials. Recent advances using conditional knock out mice also show the same molecular mechanisms for Merkel cells mechanotransduction. These findings provide new insights into how to achieve delicate tactile sensation and may have clinical therapeutic implications.
