When Faced with Chronic Stress, why do some people develop anxiety and Depressive Symptoms Who Resilience? A protein that acts as a cannabinoid receptor and is present in the structure controling exchanges between the bloodstream and the brain could be part of the answer, according to a study publiced ​​in Nature neuroscience,

“The Protein, Called Cannabinoid Receptor Type 1 (CB1), is part of the blood-brain barrier, the dynamic structure that protects the Brain by regulating the passage of Molecules BetWene the Brain,” Explains Study Leader Caroline Ménard, A Professor At University’s Faculty of Medicine and Researcher at the Cervo Brain Research Center.

“In the context of chronic social stress, the integrity of this barrier is al aned, inflammatory molecules make their way into the brain, and anxiety and depressive symptoms appear.”

CB1 receptors are Abundant in Neurons, but they also

“Astrocytes are an essential component of the barrier,” explains Prof. Ménard. “We noticed that Mice Resilient to Stress Had more CB1 Receptors in the Barrier Than Mice With Depressive-Like Behavior or Mice Not Expeded to Stress. Receptors in the response to chronic stress. “

The research team first induced an increase in CB1 receptor abundance in mouse astrocytes by development Limited its expression only to astrocytes. When injected, this virus increases the levels of CB1 receptors in the Mice’s astrocytes but not in their neurons.

These Mice was then Subjected to Chronic Social Stress. “Each day, for five minutes, they were brght into direct contact with a dominant male. The rest of the time, a transparent divider was placed in the cage. Interaction, so it was essentially a psychosocial stress, “Says ménard.

Three weeks after the injections, the level of CB1 receptors Had more than doubled in the astrocytes of Mice in the Experimental Group.

“In these mice, baseline anxiety levels-those observed in the absence of stress-andre reduced, as was still symptoms of anxiety and depression-likers induche CB1 receptors leads to resilience by promoting vascular health in the brain, “Summarizes the results.

Other Experiments Carried Out by Her Team Showed that Mice that Had Access to an exercise wheel or think antidepressants also hai Had Higher Levels of CB1 Receptors In his Astrocytes.

In addition, examination of human brains from the douglas-ball canada brain bank in Montreal confirmed the association between CB1 receptors and depressive symptoms.

“We found that level of CB1 receptors in astrocytes was lower in People with Major Depression at the time of Death than in people with than in people without depression or that treated with the antidepressants,”

These results sugges the possibility of using molecules capable of activating CB1 receptors in astrocytes to reduce anxiety and depressive symptoms, and to increase resilience in the face of stress, the faces of stress, Researcher sugges.

“The challenge, however, is to limit their effects to astrocytes, beCause strong and prolonged activation of the same receptors in neurons can have side effects, notably on alertness, anxiety and appearance. Until we find a molecule that acts specifically on CB1 receptors in astrocytes, we can mitigate the negative repercussions of stress by taking advantage of the protectative effect of phyc Activity. “