19 – Evidence from Rats that Morphine Tolerance is a Learned Response

摘要: It is proposed that the direct analgesic effect of morphine becomes attenuated over course successive administrations narcotic by a conditioned, compensatory, hyperalgesic response elicited administration procedure, net result being tolerance. Using “hot plate” analgesia assessment situation with rats, this conditioning view tolerance supported several findings: (a) necessary to have reliable environmental cues predicting systemic effects if be observed, (b) conditioned may observed in tolerant subjects when drug are followed placebo, and (c) merely repeatedly presenting previously associated (but now presented placebo), can extinguished.