You are more sensitive than you realize, neuroscientist Frank Rice of Albany Medical College has discovered. His study of patients whose skin lacks normal nerve fibers has revealed a previously unknown source of perception that contributes to the familiar ability to feel texture, temperature, pressure, and pain: the nerve endings surrounding blood vessels and sweat glands in human skin.
Rice, neurologist David Bowsher of the University of Liverpool, and their colleagues were studying two patients who were unable to feel pain, yet somehow retained a rudimentary ability to distinguish hot from cold and rough from smooth. On examining skin samples and other biopsies, the researchers found that all of the usual nerve endings associated with skin sensation were missing. The only possible sources of feeling were the nerves of the blood vessels and glands.
Scientists knew that such nerves existed but thought they simply regulated blood flow and perspiration. The evidence from the patients examined by Rice and Bowsher suggests that the nerve cells also act as an additional sensory system. “It is very likely that these nerve endings contribute to conscious perception in all of us,” Rice says. If he is correct, problems with this previously unknown system could contribute to poorly understood pain conditions, such as migraines and fibromyalgia. Rice and a group of collaborators are gearing up to investigate this potential link by searching for malformations of the blood-vessel nerves that could affect their function.