Drinking a glass of water is often sufficient to quench thirst after exercising. But while the sensation of thirst may be satiated after just a few minutes of drinking, the process of rehydration actually takes around half an hour. The delay occurs because the brain receives signals that you drank water before the body is fully rehydrated based on the detection and measurement of osmolality levels in the gut. Osmolality represents the concentration of dissolved materials including sodium and glucose.

The laboratory of Caltech biologist Yuki Oka has worked to learn more about the gut-to-brain osmolality signaling that regulates thirst, and now his team has discovered the major sensory pathway that mediates this process.

Oka, professor of biology, Chen Scholar, and Heritage Medical Research Institute Investigator; and his lab collaborated on the research with the lab of David Anderson, Seymour Benzer Professor of Biology and Howard Hughes Medical Institute Investigator. Anderson is the Tianqiao and Chrissy Chen Institute for Neuroscience Leadership Chair and director of the Tianqiao and Chrissy Chen Institute for Neuroscience at Caltech, of which Oka is also an affiliated faculty member. A paper describing the study appears in the journal Nature on January 26.

Read more on the TCCI® for Neuroscience website

Photo credit: Caltech