Researchers Discover Link Between Brain Receptors, Cannabis, Stress And Anxiety
Source: Thailand Medical News Jan 20, 2020 4 years, 2 months, 4 weeks, 1 day, 10 hours, 37 minutes ago
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-related
anxiety 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-related behaviors.
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 in animals.
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
