(LOS ANGELES) -- According to new research from the University of Southern California, carbon dioxide, found in carbonated beverages like soda, sets off pain sensors in the nasal cavity. These sensations are similar to those triggered by mustard and horseradish, but are lower in intensity. "Carbonation evokes two distinct sensations. It makes things sour and it also makes them burn. We have all felt that noxious tingling sensation when soda goes down your throat too fast," said Emily Liman, an associate professor of neurobiology in the USC College of Letters, Arts and Sciences. The burning sensation derives from a system of nerves that are responsive to skin pressure, sensations of pain, and nasal and oral temperature. "What we did not know was which cells and which molecules within those cells are responsible for the painful sensation we experience when we drink a carbonated soda," said Liman. After pouring carbonated saline onto a dish containing nerve cells taken from the sensory circuits in the nose and mouth, the researchers discovered that the gas only activated a certain type of cell. "The cells that responded to CO2 were the same cells that detect mustard," Liman said.
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