Neuroscience Studies Reveal Brain Mechanisms Behind Anxiety and Compulsive Behavior

Researchers have identified specific brain mechanisms that may underlie anxiety and compulsive behavior, with new studies pointing to potential therapeutic targets. One study found that restoring balance in a tiny amygdala circuit reversed anxiety and social deficits in mice, while another showed brain inflammation can make behavior more deliberate, not automatic.

The first study, published in the journal iScience, identified a group of neurons in the amygdala that plays a central role in anxiety, depression-like behaviors, and social withdrawal. Researchers discovered that normalizing activity in this circuit was enough to reverse anxiety-related behaviors in mice. The work focused on the basolateral amygdala and involved genetically engineered mice with unusually high levels of the Grik4 gene, which increased the number of GluK4 glutamate receptors and made certain neurons more excitable. The animals displayed behaviors resembling anxiety and social withdrawal. By normalizing Grik4 gene activity, scientists restored communication with inhibitory neurons in the centrolateral amygdala called regular firing neurons. The treatment also reduced anxiety in wild-type mice that naturally displayed elevated anxiety levels, suggesting the mechanism may be a more universal system for emotional regulation.

Separate research from the University of Technology Sydney challenges prevailing theories about compulsive behavior. Published in Neuropsychopharmacology, the study suggests that inflammation in a key decision-making brain region actually made behavior more deliberate, not more automatic. Scientists had previously believed compulsive behaviors—seen in obsessive-compulsive disorder, substance use disorders, and gambling disorder—resulted from ingrained habits overriding self-control. Brain imaging studies show people with compulsive disorders often have inflammation in the striatum. When researchers induced inflammation in this region in rats, the animals became more goal-directed and continued adjusting their behavior based on outcomes, even in situations where habits would normally take over. The changes were traced to astrocytes, star-shaped brain support cells that multiplied and disrupted nearby neural circuits controlling movement and decision-making.

These findings suggest that some compulsive behaviors may arise from excessive, though misdirected, deliberate control rather than a loss of control. For the amygdala study, not every symptom improved after the intervention; mice continued to show deficits in object recognition memory, indicating additional brain regions may be involved. Both research teams suggest their discoveries could lead to new therapeutic approaches, with one pointing to specific neural circuits as targets for affective disorders and the other recommending medications targeting astrocytes or treatments reducing neuroinflammation.