Researchers Discover Link Between Brain Receptors, Cannabis, Stress And Anxiety
A biomolecule produced by the brain
that activates the same receptors as cannabis
is protective against stress
by reducing anxiety-causing connections between two brain
regions, Vanderbilt University Medical Center researchers report.
This new research finding, published in Neuron
journal, could help explain why some people use cannabis
when they're anxious or under stress
. It could also mean that pharmacologic treatments that increase levels of this molecule, known as "2-AG
," in the brain
could regulate anxiety
and depressive symptoms in people with stress
disorders, potentially avoiding a reliance on medical cannabis
or similar treatments.
It was observed that when mice are exposed to acute stress, a break in an anxiety-producing connection between the amygdala and the frontal cortex caused by 2-AG
temporarily disappears, causing the emergence of anxiety
Dr Sachin Patel, MD, PhD, the paper's corresponding author and director of the Division of General Psychiatry at Vanderbilt University Medical Center told Thailand Medical
News, "The circuit between the amygdala and the frontal cortex has been shown to be stronger in individuals with certain types of anxiety
disorders. As people or animals are exposed to stress and get more anxious, these two brain
areas glue together, and their activity grows stronger together."
Dr Patel further added, "We might predict there's a collapse in the endocannabinoid system, which includes 2-AG
, in the patients that go on to develop a disorder. But, not everyone develops a psychiatric disorder after trauma exposure, so maybe the people who don't develop a disorder are able to maintain that system in some way. Those are the things we're interested in testing next."
The research study also found that signaling between the amygdala and the frontal cortex can be strengthened through genetic manipulations that compromise endogenous cannabinoid signaling in this pathway, causing mice to become anxious even without exposure to stress
in some cases. This finding demonstrates that the cannabinoid signaling system that suppresses information flow between these two brain
regions is critical for setting the level of anxiety
Dr Patel, also the James G. Blakemore Professor of Psychiatry and Behavioral Sciences, Molecular Physiology and Biophysics and Pharmacology further added, "We don&
;#39;t know how or why this cannabinoid signaling system disappears or disintegrates in response to stress
, but it results in the strengthening of the connection between these two regions and heightened anxiety
behaviors in mice. Understanding what's causing that compromise, what causes the signaling system to return after a few days, and many other questions about the molecular mechanisms by which this is happening are things we're interested in following up on."
Dr David Marcus, Neuroscience graduate student and first author on the paper, and Patel are also interested in how the system reacts to more chronic forms of stress
and determining whether there are other environmental exposures that compromise or enhance this system to regulate behavior.
Reference: David J. Marcus, Gaurav Bedse, Andrew D. Gaulden, James D. Ryan, Veronika Kondev, Nathan D. Winters, Luis E. Rosas-Vidal, Megan Altemus, Ken Mackie, Francis S. Lee, Eric Delpire, Sachin Patel. Endocannabinoid Signaling Collapse Mediates Stress-Induced Amygdalo-Cortical Strengthening. Neuron, 2020; DOI: 10.1016/j.neuron.2019.12.024