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 ...