A team of researchers at the Indian Institute of Science (IISc) has identified a neural circuit in the brain that plays a crucial role in the relationship between stress and itch. Their study, published in Cell Reports in March 2026, reveals how neurons activated during stress can directly suppress the sensation of itch.
While both itch and pain are unpleasant sensations triggered by harmful stimuli, they elicit different responses. Pain typically leads to withdrawal behaviors, such as pulling away from a hot surface, whereas itch prompts scratching. Although it has long been understood that emotional states like stress can amplify these sensations, the specific mechanisms linking stress and itch had remained elusive until now.
Mapping the Neural Circuit
In this groundbreaking study, the IISc team focused on the lateral hypothalamic area (LHA), a brain region associated with stress regulation and emotional responses. Using genetically engineered mouse models, the researchers identified a specific group of neurons in the LHA that become active during acute stress.
The team conducted experiments to determine whether these stress-activated neurons influence itch. According to Jagat Narayan Prajapati, a Ph.D. student at the Center for Neuroscience (CNS) and the study’s first author, the results were surprising. “We saw that acute stress was able to suppress acute itching,” he stated.
When the researchers artificially activated these neurons, they observed a reduction in scratching behavior in models experiencing both chemically induced itch and a psoriasis-like chronic itch model. Conversely, silencing these neurons removed the stress-induced suppression of scratching, indicating their critical role in this process.
Implications for Chronic Itch Treatment
The study highlights the significance of understanding the neural circuit that connects stress and itch, potentially paving the way for new therapeutic approaches to manage chronic stress-related itching. Arnab Barik, an Assistant Professor at CNS and the study’s corresponding author, emphasized the importance of their findings. “By identifying the specific neural circuit that links stress to itch, we are opening the possibility of targeting these brain mechanisms to better manage chronic stress-induced worsening of itch.”
The research also revealed distinct differences between acute and chronic itch. In models with psoriasis-like chronic inflammation, the stress-sensitive neurons showed increased activity and responsiveness during scratching episodes. This suggests that in chronic conditions, these neurons may become more excitable, preventing the typical suppression of itch and highlighting the detrimental effects of sustained stress.
Chronic itch affects millions globally, and current treatments often focus on the skin and immune responses rather than addressing the underlying neural mechanisms. “Most current treatments for chronic itch are peripheral—they treat the symptoms, not the cause,” Barik explained. Understanding these brain circuits provides a framework for developing therapies that target the central processes underlying stress-related itch.
The IISc researchers noted that their study examined only one form of acute stress. Future investigations will aim to explore additional brain circuits and their role in how various types of stress influence itch. They also plan to examine the molecular characteristics of these neurons and how stress-related circuits evolve over time, particularly in chronic disease conditions.
This research marks a significant step in understanding the neural underpinnings of itch and its relationship with emotional states, offering hope for more effective treatments for those suffering from chronic itch conditions.
