Focal brain stimulation attenuates morphine withdrawal behaviors.

Male albino rats were stereotaxically implanted with a bipolar stimulating electrode in the periaqueductal gray and also received a subcutaneous surgical implantation of a 72-mg morphine or a placebo pellet. Seventy-two hours following pellet implantation, naloxone-precipitated withdrawal was induced. Opiate withdrawal behaviors were observed and quantified. Animals then received focal brain stimulation for 30 min after which they were again observed for opiate withdrawal behaviors. The data suggest that focal brain stimulation attenuates morphine withdrawal behaviors, specifically the recessive behaviors associated with autonomic changes. These findings are consistent with those of other studies, from which it is speculated that more than one system is involved in the mediation of opioid dependence and analgesia.