Scientists have discovered a new population of taste cells that can detect multiple types of stimuli, including chemicals from different taste qualities.
Taste buds in the mouth are critical to our survival and help us to decide whether a food is a good source of nutrients or a potential poison.
They employ three types of taste cells: Type I cells acts as support cells; Type II cells detect bitter, sweet and umami tastes; and Type III cells detect sour and salty flavors.
To better understand how taste cells detect and signal the presence of different tastes, Dr. Kathryn Medler from the University at Buffalo and colleagues used an engineered mouse model to investigate the signaling pathways that the animals use to relay taste information to the brain.
The researchers discovered a previously unknown subset of Type III cells that were ‘broadly responsive’ and could announce sour stimuli using one signaling pathway, and sweet, bitter and umami stimuli using another.
The idea that mammals might possess broadly responsive taste cells has been put forth by multiple lab groups, but previously, no one had isolated and identified these cells.
The scientists suspect that broadly responsive cells make a significant contribution to our ability to taste.
Their discovery provides new insight into how taste information is sent to the brain for processing, and suggests that taste buds are far more complex than we currently appreciate.
“Taste cells can be either selective or generally responsive to stimuli which is similar to the cells in the brain that process taste information,” Dr. Medler said.
“Future experiments will be focused on understanding how broadly responsive taste cells contribute to taste coding.”
The discovery is reported in a paper in the journal PLoS Genetics.
D. Dutta Banik et al. 2020. A subset of broadly responsive Type III taste cells contribute to the detection of bitter, sweet and umami stimuli. PLoS Genet 16 (8): e1008925; doi: 10.1371/journal.pgen.1008925