Scientists at the University of Buffalo have made a discovery that could shake up what we know about the sense of smell in humans. The breakthrough centers on a newly discovered type of taste cell with the ability to respond to different stimuli, which runs counter to conventional understanding that most of them selectively respond to individual tastes and flavors.
The work was led by biological scientist Kathryn Medler, whose team investigates the functions of the peripheral taste system and the cells in our mouths that enable us to sense chemicals in food and relay those signals to the brain.
As part of this, the researchers were studying the ways in which different taste cell types detect and signal different tastes. Three different types of taste cells populate our taste buds, with Type II cells picking up bitter, sweet and umami tastes, Type III detecting sour and salty flavors, while Type I act as support cells. But the team has uncovered one with a much broader scope.
Using engineered mouse models, the researchers were studying the signaling pathways that carry information about taste from the mouth to the brain. In doing so, they happened upon a subset of Type I support cells that were “broadly responsive” to a range of stimuli.
These taste cells, the team found, could relay signals about sour stimuli using one pathway and signals about sweet, bitter and umami using another. The notion that mammals might possess more widely responsive taste cells had been hypothesized by a number of research groups previously, but never before had these cells been isolated and identified.
Along with offering a new understanding of how taste signals are processed and passed to the brain, the findings also suggest that taste buds are a whole lot more complicated than we thought.
"Taste cells can be either selective or generally responsive to stimuli which is similar to the cells in the brain that process taste information," says Medler. "Future experiments will be focused on understanding how broadly responsive taste cells contribute to taste coding."
The research was published in the journal PLOS Genetics.
Source: PLOS via EurekAlert