Biologists at the California Institute of Technology (Caltech) have identified the origin of olfactory nerve cells, finding that neural-crest stem cells – multipotent, migratory cells unique to vertebrates that give rise to many structures in the body – play a key role in building olfactory sensory neurons in the nose.
When human noses detect a scent, two types of sensory neurons are at work. These neurons are particularly interesting because they are the only ones in our bodies that regenerate throughout adult life. However, precisely where those neurons come from in the first place has long perplexed developmental biologists.
Previous hypotheses have given credit to embryonic cells that develop into skin or the central nervous system, where ear and eye sensory neurons, respectively, are thought to originate. But the Caltech team has shown that this understanding is incorrect.
“Olfactory neurons have long been thought to be solely derived from a thickened portion of the ectoderm; our results directly refute that concept,” said Marianne Bronner, Professor of Biology at Caltech and author of a paper published March 19 in the journal eLIFE.
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