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Northwestern Scientists Identify Neurons Linked to Anxiety Induced by Cannabinoids
Researchers at Northwestern University have pinpointed a specific group of neurons in the brain that play a role in the anxiety caused by cannabinoid drugs, particularly in combination with stressful situations. Cannabinoids, including THC, are substances found in cannabis that have psychoactive properties.
In a recent study, mice were exposed to a threatening odor prior to receiving either a placebo or a synthetic cannabinoid drug to investigate the impact of cannabinoids on fear and anxiety. The mice that were given cannabinoids exhibited increased anxiety-related behaviors, such as freezing more often and avoiding the predator odor. The researchers linked these behaviors to heightened activity in a subset of brain cells called somatostatin neurons, located in the central amygdala—the brain region responsible for processing fear and stress.
By genetically silencing somatostatin neurons, the researchers observed that mice exposed to cannabinoids were less likely to exhibit avoidance behavior towards predator odors. This discovery suggests that these specific neurons significantly contribute to anxiety responses triggered by cannabinoids.
Lead author Dr. Sachin Patel, chair of the department of psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine, highlighted the implications of the findings, stating, “The results of this study may explain why positive experiences with cannabis can turn negative under stressful or fearful circumstances.”
The study, published in Nature Communications on October 2nd, employed brain imaging techniques to track neuronal activity in response to threats. The researchers also examined brain tissue to investigate how cannabinoids alter neural communication, unveiling a mechanism by which the drug reduces inhibitory processes that normally control somatostatin neurons, ultimately leading to increased neural activity.
Dr. Patel underscored the importance of understanding the impact of cannabis on brain function, especially considering the rising rates of cannabis use and associated emergency department visits due to drug side effects. Studies have linked cannabis use to long-term anxiety risks, highlighting the need for further research into the psychoactive effects of the drug.
Moreover, the researchers believe that insights gained from this study may extend beyond cannabis-related effects and offer potential strategies for alleviating anxiety symptoms. By targeting somatostatin neurons in the central amygdala, researchers hope to develop interventions that can mitigate anxiety not only in the context of cannabis use but also in broader clinical applications.
Additional contributors to the study from Northwestern University include Farhana Yasmin, Saptarnab Naskar, Danyal Zaidi, Isaac Qandil, Michelle Kwon, and Dr. Luis Rosas-Vidal. The research was supported by grants from the National Institutes of Health and the Brain and Behavior Research Foundation.
Source: www.sciencedaily.com
