Brain Circuit Unlocks Stress-Itch Mystery

Researchers at the Indian Institute of Science (IISc) have successfully mapped a neural circuit responsible for the intricate connection between stress and itch. Published in Cell Reports, this study elucidates how specific neurons activated during stressful periods can directly modulate and suppress itch sensations. This discovery sheds light on a previously poorly understood mechanism.

The investigation focused on the lateral hypothalamic area (LHA), a brain region known for its role in regulating stress and emotional states. The IISc team utilized genetically engineered mouse models to pinpoint a population of LHA neurons that activate under acute stress. Experiments demonstrated that artificially activating these stress neurons reduced scratching behavior in both short-term and chronic itch models.

Conversely, inhibiting these neurons prevented stress from alleviating itching, confirming their necessity and sufficiency in stress-induced itch suppression. This breakthrough opens possibilities for developing targeted therapies to manage chronic itch that worsens with stress. Current treatments often focus peripherally, but understanding these central brain mechanisms offers a new framework for holistic management.