Acute cannabis smoke enhanced working memory accuracy in aged male rats but impaired it in aged females, with no effects in young adults of either sex. The same smoke had minimal effects on a hippocampus-dependent memory task regardless of age or sex. Chronic oral Δ9-tetrahydrocannabinol (Δ9THC) enhanced working memory in aged rats of both sexes while not affecting young adults, and did not affect spatial learning or memory in either age group. Minimal age differences in Δ9THC pharmacokinetics were observed. Cannabis and Δ9THC can attenuate working memory impairments that emerge in aging without exacerbating age-associated hippocampus-dependent cognitive decline.
Cannabis and its psychoactive component Δ9-tetrahydrocannabinol (THC) can improve working memory in aged rats, depending on sex and route of administration. Acute cannabis smoke enhanced working memory accuracy in aged male rats but impaired it in aged females, with no effect on young adults. Chronic oral THC improved working memory in aged rats of both sexes, again with no effect on young adults. Neither cannabis smoke nor oral THC affected hippocampus-dependent memory tasks in any age group. The findings suggest that cannabis may attenuate some age-related working memory deficits without worsening other cognitive impairments, though effects vary by sex and administration route.