Researchers at the Indian Institute of Science (IISc) have identified a neural circuit in the brain that plays a pivotal role in connecting stress with the sensation of itch. Their findings, published on March 15, 2026, in the journal Cell Reports, highlight how certain neurons activated during stress can directly influence itching behavior.
The relationship between itch and pain has long intrigued scientists. Both sensations arise from harmful or irritating stimuli, yet they provoke different responses. Pain typically leads to withdrawal, such as pulling a hand away from a hot surface, while itch compels scratching. While it is well established that emotional states like stress can amplify these sensations, the neural mechanisms linking stress specifically to itch have remained less understood.
Exploring Brain Mechanisms
The IISc team concentrated their research on the lateral hypothalamic area (LHA), a region known for regulating stress, motivation, and emotional states. Utilizing genetically engineered mouse models, they pinpointed a specific group of neurons in the LHA that become active during acute stress.
Dr. Jagat Narayan Prajapati, a Ph.D. student at the Center for Neuroscience (CNS) and the study’s first author, shared insights on the unexpected findings. “We ran some pilot experiments and surprisingly saw that acute stress was able to suppress acute itching,” said Prajapati. The researchers discovered that activating these stress neurons led to a significant decrease in scratching behavior in both chemically induced and psoriasis-like chronic itch models. In contrast, silencing these neurons resulted in the loss of stress-related itch suppression.
These discoveries indicate that the identified neurons are both essential and sufficient for mediating stress-induced reductions in itch. Dr. Arnab Barik, Assistant Professor at CNS and the study’s corresponding author, elaborated, “We show that a specific circuit in the lateral hypothalamus can suppress itch during acute stress, revealing how the brain directly links emotional states to sensory perception.”
Implications for Chronic Itch Treatment
The research holds significant implications for managing chronic itch, a condition affecting millions globally. Current therapies primarily target the skin and immune system, but the new findings underscore the brain’s critical role in shaping itch perception. “Most current treatments for chronic itch are peripheral—they treat symptoms, not the cause,” Barik explained. “Understanding these circuits gives us a framework for eventually developing therapies that address the central mechanisms underlying stress-related itch.”
The study also highlighted differences between acute and chronic itch. In mouse models exhibiting psoriasis-like chronic inflammation, the same stress-sensitive neurons displayed heightened activity and responsiveness during scratching episodes. This suggests that in these models, the stress-sensitive neurons become more excitable, which may prevent the typical suppression of itch and illustrate the detrimental effects of chronic stress.
While this research examined one form of acute stress, the authors acknowledge that additional brain circuits are likely involved in how various types of stress impact itch. Future research will focus on identifying the molecular characteristics of these neurons and understanding how stress-related circuits evolve over extended periods, particularly in chronic disease conditions.
The findings from this study could pave the way for more effective treatments for chronic itch, providing hope for individuals suffering from this often debilitating condition.
