Recent research from the Indian Institute of Science (IISc) has revealed a significant neural circuit in the brain that plays a crucial role in the relationship between stress and itch. The study, published in Cell Reports in March 2026, demonstrates how specific neurons activated during stressful situations can directly influence the sensation of itch.
Itch and pain, while both unpleasant, evoke different responses in individuals. Pain typically prompts withdrawal, such as pulling a hand away from a hot surface, whereas itch leads to scratching. Although the impact of emotional states like stress and anxiety on pain is well-documented, their effects on itch have not been thoroughly explored until now.
Investigating the Neural Mechanisms
The research team at IISc focused on the lateral hypothalamic area (LHA), a brain region known for regulating stress and emotional states. Using genetically modified mice, the researchers pinpointed a specific group of neurons in the LHA that become active during acute stress. They conducted experiments to determine if these stress-activated neurons could directly impact itch responses.
According to Jagat Narayan Prajapati, a Ph.D. student and the study’s first author, initial experiments revealed an unexpected result: “Acute stress was able to suppress acute itching.” When the team artificially stimulated these stress neurons, they observed a reduction in scratching behavior in both chemically induced acute itch and a model simulating chronic itch, similar to psoriasis. Conversely, silencing these neurons eliminated the stress-related reduction in scratching, proving their critical role in this phenomenon.
This discovery suggests that the LHA contains a specific circuit capable of suppressing itch during stressful periods, linking emotional states directly to sensory perception.
Implications for Chronic Itch Treatment
The implications of this research are significant, particularly for managing chronic itch exacerbated by stress. Arnab Barik, an Assistant Professor at IISc and the corresponding author of the study, noted, “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 study also highlighted differences between acute and chronic itch. In models exhibiting psoriasis-like chronic inflammation, stress-sensitive neurons displayed heightened activity and responsiveness during scratching episodes. This indicates that chronic stress may alter the functionality of these neurons, potentially preventing the suppression of itch and underscoring the detrimental effects of prolonged stress.
Chronic itch affects millions globally, and current treatments primarily target the skin and immune responses. Barik emphasized the necessity of addressing the brain’s role in itch perception: “Most current treatments for chronic itch are peripheral—they treat the symptoms, not the cause.”
Looking forward, the researchers acknowledge that their study examined only one form of acute stress. They anticipate that other brain circuits may also influence how different stress types affect itch. Future investigations will aim to clarify the molecular characteristics of these neurons and explore how stress-related circuits evolve over time, especially in chronic conditions.
The findings from this research provide a promising framework for developing therapies that could tackle the central mechanisms behind stress-related itch, offering hope to those who suffer from this debilitating condition.
