Pain: its physiology and rationale for management. Part II. Analgesic systems of the CNS.

The analgesic effects of morphine and other opiates have long been recognized, but the mechanisms underlying these effects have only recently been uncovered. First, opiate receptors were discovered and their distribution throughout the central nervous system mapped. Then endogenous morphine-like copmounds, called endorphins and enkephalins, were identified. One of the most promising aspects of understanding the physiology and pharmacology of these endogenous opiates is conquering control over pain.