Mechanism of touch sensitivity in rapidly-adapting mechanosensory corpuscles

The ability to sense the world though physical contact is essential for all living organisms. In vertebrates, transient touch and vibration are detected by Pacinian corpuscles, but the mechanism of their function is poorly understood. Pacinian corpuscles are innervated by rapidly-adapting mechanoreceptor afferents, which detect touch due to expression of mechanically activated ion channels. The mechanoreceptor is surrounded by inner core cells, which are thought to provide auxiliary non-sensory support for the mechanoreceptor. Here, we will functionally test the hypothesis that inner core cells of Pacinian corpuscles are active touch sensors. We seek to reveal the molecular mechanism of touch sensitivity and touch-evoked excitability in inner core cells, and determine the effect of inner core cell activation on mechanoreceptor function. To do this, we will use bill skin of tactile specialist ducks, which contains a high density of Pacinian corpuscles accessible for electrophysiological manipulations. Because Pacinian corpuscles are present in the skin or internal organs of most vertebrates, including all mammals, our results will further our understanding of general molecular and cellular mechanisms of touch detection.