Scientists Discover Key Protein in Resilience to Stress

When Faced with Chronic Stress, Why from the Some People Develop Anxiety and Depressive Symptles While Others Show Resilience? A protein that acts a cannabinoid receptor and is present in the structure controlling exchanges Between the Bloodstream and the Brain Could Be part of the ANSWER, According to Study Published in Nature Neuroscience.

“The Protein, Called Cannabinoid Receiver Type 1 (CB1), is part of the Blood-Brain Barrier, The Dynamic Structure That Protects The Brain by Regulation of Molecules Beteen The Bloodstream and the Brain,” Explains Study Leader Caroline, Professor at Université Laval’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 Altered, Infummary Molecules Make Their Way Into the Brain, and Anxiety and Depressive Symptles Appear.”

CB1 Receptors are abundant in neurons, buty’re also Found in Astrocytes, Star-Shaped Cells Allowing Communication Between The Brain’s Blood Vessels and Neurons.

“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 Exposed to Stress. That gave us the idea to Investigate The Role of Astrocytic CB1 Receptors in the Response To Chronic Stress.”

The Research Team First Induced an Increase in Cb1 Receiver Abundance in Mouse Astrocytes By Developing The Viral Vector That Contained The Genetic Material Coding For the CB1 Receiver As well as Mechanism That Limited Its Expression Only to Astrocytes. WHEN INJECTED, THIS VIRUS INCREASED THE LEVES OF CB1 RECEIPTORS IN THE MICE’S ASTROCYTES BUT NOT IN THEIR NEUROONS.

These Mice Were then Subjected to Chronic Social Stress. “Each Day, for Five Minutes, They Were Brought into Direct Contact with a Dominant Male. The Rest of the Time, the Transparent Divider Was Placed in the Cage. 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-Wer Reduced, the Were Sympts of Anxiety and Depression Like Behaviors induced by Social Stress. Overexpression of CB1 Receptors Leads to Resilience by Promoting Vascular Health in The Brain,” Summarides The Researcher.

Other Experiments Carried Out by Her Team Showed That Mice That Had Access To An Exercise Wheel or Those Given Antidepressants Also Had Higher Levels of CB1 Receptors in Their Astrocytes.

In Addition, Examination of Human Brains from the Douglas-Bell Canada Bran Bank in Montreal Confirmed the Association Between CB1 Receptors and Depressive Symptoms.

“We Found That the Level of CB1 Receptors in Astrocytes Was Lower In People With Major Depression at the Time of Death Than In People Without Depress or Those Treated with Antidepressants,” Says Menard.

These results suggest the possibilities of Using molecules capable of activation cb1 receptors in astrocytes to reduce anxiet and depressive sympts, and to increase resilience in the face of stress, The Research Suggers.

“The Challenge, However, is to Limit Their Effects to Astrocytes, Because Strong and Prolonged Activation of the Same Receptions in Neurons Can have Side Effects, Notably on Alertness, Anxiety and Appetite. Astrocytes, We Can Mitigate The Negative Repercussions of Stress by Taking Advantage of the Protective Effect of Physical Activity. “