Scientists discovered a small group of brain cells that can make mice feel anxious, act sad, and avoid other mice. When they fixed the activity of these cells, the bad behaviors went away.
Where the important cells live
The cells are inside the amygdala, a part of the brain that helps us feel fear and worry. The team looked at a special set of neurons in the basolateral amygdala.
In their mouse model, a gene called Grik4 was turned up too high. This made the neurons fire too much because they had extra GluK4 receptors.
Making the circuit work again
Researchers used genetic tools to lower the activity of the Grik4 gene just in the basolateral amygdala. This helped the neurons talk normally with the inhibitory cells in the neighboring centrolateral amygdala.
After the correction, the mice behaved more like normal mice. They explored open areas, liked new toys, and interacted with other mice without fear.
Does it work for other mice?
To see if the finding was specific to the engineered mice, the scientists tried the same fix on regular mice that naturally showed high anxiety. Those mice also calmed down, suggesting the circuit is a common anxiety pathway.
What still needs work
Not every problem disappeared. The mice still had trouble remembering objects, which means other brain areas such as the hippocampus may also be involved.
Still, the study shows that targeting a tiny brain circuit could become a precise way to treat anxiety and related mood disorders.