[Motor or aversive effects associated with analgesic effects induced by electric stimulation of the periaqueductal gray matter in rats]

Abstract

The analgesia induced in the Rat by a stimulation applied to the periaqueductal gray matter (PAG) was reevaluated. With the exception of a few stimulation sites located in the ventral PAG, the stimulation-induced analgesia was generally accompanied by strong aversive effects (dorsal and dorsolateral PAG) or motor effects (ventral PAG). These results raise the problem of a possible involvement of "stress-produced analgesia" and motor disturbances in the production of analgesia by PAG stimulation.