A research team led by Professor Lee Young Seok (Department of Bio-Fermentation Convergence, Kookmin University; President: Jeong Seung Ryul), with co-first authors Purisonnali and Sang Ji Un, has identified a brain-centered neuroendocrine circuit that dynamically regulates salt intake based on an animal's internal salt status. The findings will be published in the February 24, 2026 issue of the prestigious international journal Proceedings of the National Academy of Sciences (PNAS) (published online February 21: www.pnas.org/doi/10.1073/pnas.2530544123).

○ The ‘brain,’ not taste, directly judges the body's salt status and regulates rejection responses
Taste is generally known to be perceived when taste receptors on the tongue react to external taste substances. The research team previously discovered sensors detecting saltiness in the mouth and esophagus (https://elifesciences.org/articles/93464).
However, when the body's salt (NaCl) concentration is already high, it instinctively limits further salt intake to maintain homeostasis. Using a fruit fly model, the team revealed that specific neurons in the brain directly sense salt concentration within the body and regulate the intake rejection response.

○ Insulin and Leukokinin signaling pathways play a key role
The research revealed that insulin-producing neurons (MNCs) in the fruit fly brain and Leukokinin (Lk) neurons—the human tachykinin analog—are central to this process.
When salt concentration in the body is high, these neurons activate, maintaining the aversion response to high salt concentrations and preventing excessive intake. Conversely, when salt becomes scarce, leucokinin signaling stimulates insulin-producing cells, altering the taste preference (liking) to encourage consumption of high-salt concentrations that would normally be avoided.
Notably, this study demonstrated that these neurons function as a ‘central sodium sensor,’ directly detecting the sodium concentration of surrounding fluids without relying on external signal transmission (e.g., from the tongue). This research was supported by the Basic Research Program (Mid-Career Research) of the National Research Foundation of Korea.

○ New therapeutic clues anticipated for salt intake imbalance diseases like hypertension and diabetes
Professor Lee Young Seok stated, “We have identified an endocrine mechanism where the brain directly monitors the body's salt concentration and modifies behavior.” He added, “This principle shares similarities with the salt balance maintenance mechanism in mammals. It could explain why patients with hypertension or diabetes consume high-salt diets and suggest related therapeutic targets, providing crucial foundational data for human applications.”