Cannabidiol attenuates deficits of visuospatial associative memory induced by D9tetrahydrocannabinol

M. Jerry Wright Jr, Sophia A. Vandewater and Michael A. Taffe

Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla,
CA, USA

British Journal of Pharmacology, 2013, 170, 1365–1373

 

BACKGROUND AND PURPOSE
Recent human studies suggest that recreational cannabis strains that are relatively high in cannabidiol (CBD) content produce less cognitive impairment than do strains with negligible CBD and similar D9tetrahydrocannabinol (THC) content. Self-selection in such studies means it is impossible to rule out additional variables which may determine both cannabis strain selection and basal cognitive performance level. Controlled laboratory studies can better determine a direct relationship.

EXPERIMENTAL APPROACH
In this study, adult male rhesus monkeys were assessed on visuospatial Paired Associates Learning and Self-Ordered Spatial Search memory tasks, as well as additional tests of motivation and manual dexterity. Subjects were challenged with THC (0.2, 0.5 mg·kg-1, i.m.) in randomized order and evaluated in the presence or absence of 0.5 mg·kg-1 CBD.

KEY RESULTS
CBD attenuated the effects of THC on paired associates learning and a bimanual motor task without affecting the detrimental effects of THC on a Self-Ordered Spatial Search task of working memory. CBD did not significantly reverse THC-induced impairment of a progressive ratio or a rotating turntable task.

CONCLUSIONS AND IMPLICATIONS
This study provides direct evidence that CBD can oppose the cognitive-impairing effects of THC and that it does so in a task-selective manner when administered simultaneously in a 1:1 ratio with THC. The addition of CBD to THC-containing therapeutic products may therefore help to ameliorate unwanted cognitive side-effects.

LINKED ARTICLE
This article is commented on by Mechoulam and Parker, pp 1363–1364 of this issue. To view this commentary visit http://dx.doi.org/10.1111/bph.12400

Keywords : cannabis; marijuana; Macaca mulatta; working memory

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