Uncoupling cannabinoid effects

An endocannabinoid ? which acts on the same receptors as the active component in marijuana ? is shown to be involved in a wide range of neurological processes including pain sensation, reports a paper online in Nature Chemical Biology.

Cannabinoid signalling in the nervous system affects memory, appetite and mood, making it an attractive therapeutic target. Two different endocannabinoids, chemicals that bind to the cannabinoid receptors, induce these varied neurological effects. However since both chemicals signal through the same receptors, it has been difficult to match an endocannabinoid with its specific behavioural effects.

Benjamin Cravatt and colleagues have developed an inhibitor of the enzyme that breaks down an endocannabinoid, arachidonoylglycerol known as 2-AG. By blocking this enzyme, levels of 2-AG increased in mouse brains, which led to decreased pain sensation, hypothermia and decreased movement ? providing evidence for the specific role of 2-AG in these processes. This inhibitor will provide an important tool for further investigating the neurological effects of 2-AG and may also provide a starting point for designing new pharmaceuticals.