“While recreational marijuana users may seek the full range of its effects, broad medical use of THC—including for pain, nausea, and anxiety—is hindered by them.

In a new study, Xavier Viñals, Estefania Moreno, Peter McCormick, Rafael Maldonado, Patricia Robledo, and colleagues demonstrate that the cognitive effects of THC are triggered by a pathway separate from some of its other effects.

That pathway involves both a cannabinoid receptor and a serotonin receptor, and when this pathway is blocked, THC can still exert several beneficial effects, including analgesia, while avoiding impairment of memory.

The results of this study are potentially highly important, in that they identify a way to reduce some of what are usually thought of as THC’s unwanted side effects when used for medicinal purposes while maintaining several important benefits, including pain relief.

The widening acceptance of a role for THC in medicine may be accelerated by the option to reduce those side effects by selective pharmacological disruption or blocking of the heteromer.”

http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002193