Researchers at Vanderbilt University have found that cannabinoid receptors, through which marijuana applies its effects are in a key emotional hub of the brain which helps to regulate anxiety and the flight-or-fight response.
This is the first time cannabinoid receptors have been identified in the central nucleus of the amygdala in a mouse model.
Sachin Patel, M.D., Ph.D., the paper’s senior author and professor of psychiatry and of molecular physiology and biophysics says that the discovery may help explain why marijuana users say they take the drug mainly to reduce anxiety.
The study also showed for the first time how nerve cells in this part of the brain make and release their own natural endocannabinoids.
As the legalization of marijuana spreads across the country more people, and especially young people, whose brains are still developing are trying it.
Patel says that previous studies have suggested that while marijuana’s “exogenous” cannabinoids can reduce anxiety, chronic use of the drug down-regulates the receptors, paradoxically increasing anxiety. This can trigger “a vicious cycle” of increasing marijuana use that in some cases can lead to addiction.
“We know where the receptors are, we know their function, we know how these neurons make their own cannabinoids. Now, can we see how that system is affected by …….. stress and chronic marijuana use? It might fundamentally change our understanding of cellular communication in the amygdala,” says Patel. The study is in the current issue of the journal Neuron. Medical News Today 3/10/14