Endocannabinoids in cognition and dependence

Cannabis use is associated with a wide range of pharmacological effects, some of which have potential therapeutic benefit while others result in negative outcomes. Acute cannabinoid intoxication has been well documented to produce deficits in cognitive functioning with concomitant changes in glutamatergic, GABAergic, and cholinergic neurochemical systems in the hippocampus, each of which has been implicated in memory. Additionally, cannabis-dependent individuals abstaining from this drug can undergo a constellation of mild withdrawal effects. The use of the CB1 cannabinoid receptor antagonist SR141716A and transgenic mice lacking the CB1 receptor are critical tools for investigating the role of the endocannabinoid system in cognition, drug dependence, and other physiological processes. Converging evidence in which performance in a variety of memory tasks is enhanced following either SR141716A treatment or in CB1 receptor knockout mice indicates that this system may play an important role in modulating cognition. There are also indications that this system may function to modulate opioid dependence. The purpose of this review is to describe recent advances that have furthered our understanding of the roles that the endocannabinoid system play on both cognition and drug dependence. (C) 2002 Published by Elsevier Science Ltd.