Recent findings from ongoing research at University of Alabama at Birmingham have provided new insights into the functioning of Merkel discs, small sensory organs in the fingertips that enable our highly discriminatory sense of touch. The new knowledge may be useful, according to the research team, in informing our understanding of tactile allodynia, in which intense pain is caused by gentle touch, as well as why patients with diabetes may experience a loss of touch sensation. Edward Ernst, MD, Endowed Professor in the UAB Department of Anesthesiology and Perioperative Medicine, stated “Touch-induced pain is also commonly seen in clinical conditions such as fibromyalgia, traumatic injury and in inflammation from sunburn. Our new findings may have profound implications in these conditions.” The findings are published in Proceedings of the National Academy of Sciences.
A Merkel disc is comprised of a Merkel cell and a closely associated nerve ending that branches from a single sensory nerve. The process by which the physical pressure of a light touch gets transduced from a mechanical force to an electrical nerve signal in the disc has not been well understood. A first step was the 2014 discovery by UAB researchers of a new ion channel, Piezo2, in the Merkel cells that functions as the transducing molecule. In the current findings, they report that Piezo2 triggers the Merkel cell to release serotonin, which then crosses the nerve synapse, activating 5-HT receptors and triggering nerve impulses. This, according to the authors, suggests that agents that regulate serotonin uptake may enable the alteration of this epidermal transmission, an avenue of potentially useful therapeutic study.
Read more about the research findings here.
The journal abstract may be read here.