Cannabinoid receptor surprise

Credit: © Dr Neal Scolding / Photo Researchers, Inc." /> Credit: © Dr Neal Scolding / Photo Researchers, Inc. The paper: M. Van Sickle et al., "Identification and functional characterization of brainstem cannabinoid CB2 receptors," Science, 310: 329?32, 2005. (Cited in 80 papers) The finding: While studying the anti-emetic effects of endogenous cannabinoids in ferrets, Keith Sharkey at the University of Calgary, Canada and collea

Andrea Gawrylewski
Oct 1, 2007
<figcaption> Credit: © Dr Neal Scolding / Photo Researchers, Inc.</figcaption>
Credit: © Dr Neal Scolding / Photo Researchers, Inc.

The paper:

M. Van Sickle et al., "Identification and functional characterization of brainstem cannabinoid CB2 receptors," Science, 310: 329?32, 2005. (Cited in 80 papers)

The finding:

While studying the anti-emetic effects of endogenous cannabinoids in ferrets, Keith Sharkey at the University of Calgary, Canada and colleagues found that agonists to the CB2 cannabinoid receptor reduced emetic events, even though only CB1 receptors were thought to be present in neurons. Probing further, Sharkey's group found CB2 messenger RNA and protein in three areas of rat brain.

The surprise:

CB2 receptors had "been identified before in the immune system," Sharkey says. "They were considered to be the peripheral CB receptors," with all effects of cannabinoids in the brain attributed to the CB1 receptor.

The brain:

This paper is only "half of the story," says Emmanuel Onaivi, assistant professor at William Patterson University,...

The numbers:
Episodes of emesis
With emetic agent alone: >5
With endocannabinoid VDM11 or 2-AG: <2.5