IISc researchers find out how the brain suppresses itch during stress

IISc researchers unveil a brain circuit that suppresses itch during stress, advancing understanding of its neural mechanisms and potential treatments.

Researchers at the Indian Institute of Science (IISc) have mapped a neural circuit in the brain involved in the complex relationship between itch and stress. Their findings, published in Cell Reports, reveal how specific neurons activated during stress can directly regulate itch.

IISc said that itch and pain are both unpleasant sensations triggered by harmful or irritating stimuli, but they lead to different behavioural responses.

While pain typically causes us to withdraw (such as pulling our hand away from a fire), itch drives scratching.

“Scientists have long known that emotional states such as stress and anxiety can influence the intensity of these sensations. While the neural mechanisms linking stress and pain have been studied extensively, the effect of stress on itch has remained poorly understood,” IISc said.

In the new study, the IISc team focused on the lateral hypothalamic area (LHA), a region in the brain known to regulate stress, motivation, and emotional states. Using genetically engineered mouse models, the researchers identified a specific population of neurons in the LHA that become active during acute stress.

The researchers then tested whether these stress-activated neurons directly influence itch. “We ran some pilot experiments, and we saw that, surprisingly, acute stress was able to suppress acute itching,” said Jagat Narayan Prajapati, PhD student at the Centre for Neuroscience (CNS), IISc, and first author of the study.