Differential Growth and Generation of Stem Cells and Receptor Cells in Taste Buds and Olfactory Epithelium
Receptor cells in taste buds and olfactory epithelium turn over at different rates than do stem cells in these structures.
There are multiple cell types in taste buds and in olfactory epithelium. Among these cells are receptor cells which are of multiple types and play multiple roles in taste and smell function and stem cells which are singular in their character and play different roles than do receptor cells. Receptor cells are unique in that none of them contain blood vessels, lymphatics or exhibit mitosis. Yet, they metabolize rapidly turning over as rapidly as every 24 hours. On the other hand stem cells turn over slowly
Receptor cells, which are turning over rapidly, depend upon the presence of these stem cells which are present in both taste buds and olfactory epithelium. However, these stem cells do not turn over rapidly but are more permanent features of taste buds and olfactory epithelium. Indeed these stem cells are functionally immortal. They respond to specific chemical moieties which allow them to generate the multiple receptor cells which comprise most of the cellular components of taste buds and olfactory epithelium. Receptor cells “live” for relatively short periods of time since they are exposed to the outside environment and are thereby subject to local injury or local interference. They regenerate quickly because they are so important for taste and smell function and for normal functions of eating and smelling. While the receptor cells turn over rapidly the stem cells, which appear to be anatomically more protected than receptor cells, “live” for long periods of time and do not turn over rapidly. Stem cells depend upon chemical moieties for their growth and perpetuation which are presently not well known. These chemical moieties upon which stem cells depend for their growth may be and probably are different from those moieties which they secrete to stimulate sensory receptors. It is this interaction between persistent stem cell stability and transient receptor function which enables these systems to allow us to taste and smell.
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