Amygdala Neurons Linked to Anxiety, Depression
Restoring neuronal balance reverses pathological behaviors in mice.
New research pinpoints a specific group of neurons in the amygdala, a brain region responsible for emotion regulation, as critical in conditions like anxiety and depression. The study reveals that re-establishing equilibrium in this area can reverse these behaviors.
Key Discovery in Amygdala Function
The team led by Juan Lerma at the Institute for Neurosciences (IN) discovered that targeted manipulation of neurons within the amygdala could mitigate symptoms of anxiety and social withdrawal in mice. The amygdala is already known to contribute significantly to emotional responses, but this study defines how specific neurons influence such behaviors.
“We already knew the amygdala was involved in anxiety and fear, but now we’ve identified a specific population of neurons whose imbalanced activity alone is sufficient to trigger pathological behaviors.”
—Juan Lerma, Institute for Neurosciences (IN)
Experimental Design and Results
Researchers utilized genetically modified mice with overexpression of the Grik4 gene, which increased glutamate receptors and elevated neuronal excitability. These mice exhibited behaviors associated with anxiety and social deficits mirroring those seen in autism or schizophrenia.
By normalizing the gene expression in the basolateral amygdala, the scientists re-established communication with inhibitory neurons in the centrolateral amygdala. Álvaro García, the study’s first author, noted the impact of this adjustment.
According to the Anxiety & Depression Association of America, anxiety disorders affect 31.1% of adults in the United States at some point in their lives (ADAA).
Reversal of Anxious Behaviors
Electrophysiological techniques and behavioral tests were administered to assess anxiety, depression, and social interactions in the rodents. Following this, genetic engineering and modified viruses were used to selectively correct alterations in the basolateral amygdala, yielding notable changes in both neuronal activity and behavior.
The team also tested these procedures on wild-type mice that showed inherent anxiety; the treatment was also effective in reducing their anxiety. Lerma suggests this may represent a general principle for emotion regulation in the brain.
Future Therapeutic Applications
While some cognitive functions like object recognition memory remained uncorrected, potentially involving other brain areas such as the hippocampus, the study highlights possibilities for new therapies. According to Lerma, targeting specific neural circuits could offer a localized strategy for treating affective disorders.