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If further research proves successful, it could change how we treat anxiety and depression.
Deep within the brain, scientists have pinpointed a cluster of cells whose overactivity can spark anxiety, depression, and social withdrawal.
By restoring balance in this small but powerful region, they discovered, these effects can be reversed.
The work, led by Juan Lerma and his team at Spain’s Institute for Neurosciences (IN), was published in iScience earlier this year and could reshape how scientists think about treating mood disorders.
A new emotional link
The amygdala is known as the brain’s emotional control center. Lerma’s team focused on a section called the basolateral amygdala, identifying a group of neurons whose excessive firing disrupts emotional balance.
Using genetically modified mice that overproduce the GluK4 receptor—regulated by the Grik4 gene—the researchers found that these neurons became overly excitable, breaking normal communication between brain regions.
The mice displayed anxiety and social avoidance similar to symptoms in human mood and developmental disorders.
When scientists used genetic tools to normalize Grik4 levels only in the basolateral amygdala, communication with another group of inhibitory neurons—the “regular firing neurons” in the centrolateral amygdala—was restored.
Balance restored
This one correction was enough to eliminate anxious and antisocial behaviors. “That simple adjustment was enough to reverse anxiety-related and social deficit behaviors, which is remarkable,” said first author Álvaro García.
The team confirmed the changes using detailed electrophysiological recordings that track how neurons communicate, along with behavioral tests measuring anxiety and depression. Treated mice were calmer, more social, and less fearful of open spaces.
Even naturally anxious mice—those not genetically modified—responded to the same treatment.
According to Science Daily, Lerma said this finding suggests the mechanism could reflect a general principle in how the brain regulates emotion.
“This validates our findings and gives us confidence that the mechanism we identified is not exclusive to a specific genetic model,” he explained.
Beyond mood control
Not all functions recovered fully. Tests of object recognition memory showed only partial improvement, pointing to the hippocampus and other brain regions as additional players in emotional and cognitive health.
Still, the discovery that modulating excitability in a small neural circuit can restore emotional balance marks a significant step forward.
Rather than altering brain chemistry with drugs, researchers see a future in precision-based interventions that target specific cell networks.
Toward targeted therapies
This study adds to growing evidence that emotional disorders stem from disruptions in defined neural circuits.
Adjusting their activity could offer faster, safer, and more effective treatments for anxiety, depression, and social dysfunction.
Funded by the Spanish State Research Agency, the Severo Ochoa Excellence Program, and the European Regional Development Fund, the study underscores how neuroscience is shifting toward circuit-based precision medicine.
The next challenge, Lerma said, is testing whether similar mechanisms exist in humans and whether these targeted adjustments could help people with chronic anxiety or depression.
If confirmed, such work could pave the way for brain-based therapies that restore emotional stability without heavy medication.
Sources: iScience, Institute for Neurosciences (IN), Reuters, BBC, AP
