Researchers at the Indian Institute of Science (IISc) have discovered a neural circuit in the brain that plays a crucial role in how stress impacts the sensation of itch. Their study, published in Cell Reports in March 2026, reveals that specific neurons activated during stressful situations can directly regulate itch sensations. This finding provides valuable insights into the complex interplay between emotional states and sensory perception.
The study highlights the differences between itch and pain, both of which are unpleasant sensations triggered by harmful stimuli. While pain typically leads to withdrawal behaviors, such as pulling away from a hot surface, itch provokes scratching. Researchers have long understood that emotional states, particularly stress and anxiety, can amplify these sensations, but the neural mechanisms linking stress and itch have remained largely unexplored.
Investigating the Brain’s Itch Circuitry
The IISc research team focused on the lateral hypothalamic area (LHA), a brain region known to regulate stress and emotional states. Using genetically modified mouse models, they identified a distinct population of neurons within the LHA activated during acute stress. The researchers aimed to determine whether these neurons directly influence itch sensation.
“We conducted pilot experiments and found that unexpectedly, acute stress was capable of suppressing acute itching,” said Jagat Narayan Prajapati, a Ph.D. student at the Center for Neuroscience (CNS) and the study’s first author. When the team artificially activated the stress neurons, they observed a decrease in scratching behavior in models of both short-term chemically induced itch and a psoriasis-like chronic itch model. Conversely, silencing these neurons eliminated the stress-induced reduction in scratching, demonstrating that these neurons are essential for the mechanism of itch suppression during stress.
Arnab Barik, Assistant Professor at CNS and the corresponding author, noted, “We demonstrate 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.”
Potential Implications for Chronic Itch Treatment
The identification of the neural circuit connecting stress and itch opens new avenues for managing chronic itch exacerbated by stress. Chronic itch affects millions globally, and current treatments primarily target skin and immune responses. The new findings underscore the brain’s significant role in shaping itch perception.
“Most current treatments for chronic itch are peripheral—they address the symptoms rather than the underlying causes,” Barik explained. “The interaction between stress, anxiety, and sensations like itch occurs in the brain. Understanding these circuits provides a framework for developing therapies that tackle the central mechanisms underlying stress-related itch.”
The study also revealed differences between acute and chronic itch responses. In mouse models with psoriasis-like chronic inflammation, the stress-sensitive neurons exhibited increased activity and responsiveness during scratching episodes. This suggests that in chronic conditions, these neurons become more excitable, altering their activity patterns and inhibiting their ability to suppress itch, which highlights the detrimental effects of chronic stress.
Looking ahead, the researchers acknowledge that their study focused on a specific form of acute stress, indicating that additional brain circuits likely influence how various types of stress affect itch. Future research will aim to uncover the molecular characteristics of these neurons and explore how stress-related circuits evolve over time, especially in chronic disease contexts.
The collaborative efforts of Aynal Haque and Giriraj Sahu, Assistant Professor at the Molecular Biophysics Unit at IISc, contributed significantly to this research, paving the way for a deeper understanding of the brain’s role in itch perception and its modulation by stress.
