AM281, Cannabinoid Antagonist/Inverse agonist, Ameliorates Scopolamine-Induced Cognitive Deficit

Cannabinoids have been implicated in memory deficit. We examined the effect of AM281, cannabinoid antagonist/inverse agonist in prevention of scopolamine-induced cognitive deficit. Object recognition task was used to evaluate memory in mice. Exploration time in the first and the second trial was recorded. The differences in exploration between a previously seen object and a novel object in second trial were taken as an index of memory. Scopolamine and AM281 were administrated at the same time, 40 min before second trial in the treatment group.Object discrimination was impaired after scopolamine (2 mg/kg; IP) administration. AM281 (2.5, 5 mg/kg; IP) significantly restored object recognition ability in mice treated with scopolamine by 75%.This study extends earlier findings, suggesting the interaction of cannabinoid and cholinergic system in memory. Additionally cannabinoid antagonists seem to show variable pharmacological properties.