Perl, 64, was recognized for his discovery of nociceptors, nerve endings in skin and tissue that convey information about pain-causing stimuli, and for his finding that nociceptors engage some specific central neural mechanisms. He also found that nociceptors have the ability to become sensitized to repeated stimulation, so that normally nonpainful actions, such as the touch of a hand, cause pain--for example, in cases of sunburn.
Nociceptors--so named because they detect noxious stimuli--were first hypothesized to exist at the turn of the century by Sir Charles Sherrington, who won the Nobel Prize in medicine or physiology in 1932. "The basic problem," says Perl, "was that no one had found these. Sherrington's prediction had been forgotten over the years; no one had used that line of thinking." In the mid-1960s, Perl recalls, while he and colleague P.R. Burgess were "in the process of doing a systematic analysis of sensory fibers" at the University of Utah, they found evidence that confirmed Sherrington's hypothesis (Journal of Physiology [London], 190:541-62, 1967). "We looked at each other across the experimental table; I guess we both understood what we had seen."
Prior to this discovery, Perl explains, the study of pain was "pretty much a black box; you couldn't relate [pain] to specific neural activity." Since nociceptors have been found to exist, researchers have been able to evaluate their activity and how it is affected by experimental drugs.
In subsequent experiments in the 1960s, Perl and his associates found that there are different types of nociceptors, each with different underlying mechanisms. Thus, he says, "there's not going to be a single silver bullet that's going to reduce pain in all circumstances."
Perl received his B.S. degree in 1947 and his M.D. in 1949 from the University of Illinois (Champaign and Chicago campuses). He has been a professor of physiology at UNC since 1971 and Sarah Graham Kenan Professor since 1983. Before coming to UNC, he was a professor of physiology at the University of Utah's School of Medicine in Salt Lake City. He is a founder and former acting president of the Society for Neuroscience.