Researchers from the University of Miami Miller School of Medicine and Duke Institute for Brain Sciences say they have discovered a thriving neuron ‘nursery’ in the olfactory neuroepithelium, a section of adult human nose tissue.
A tissue section from a human nasal biopsy. The red staining outlines olfactory neurons and the blue staining is counterstain for cell nuclei. Image credit: Brad Goldstein.
Previously, studies had been limited to nasal tissue samples from mice.
In the human tissue samples used in the new study, senior author Dr. Brad Goldstein and colleagues found that immature neurons produced by stem cells represented more than half of the neurons in the samples, suggesting that new neurons were produced in the tissue.
“We do not fully understand why people lose their sense of smell, which can occur for many reasons, and our data sets provide a wealth of information about the cell populations present in adult olfactory tissue,” Dr. Goldstein said.
“This is an important step in developing treatment strategies for conditions when this tissue may be damaged.”
Approximately one in eight Americans over age 40 — up to 13.3 million people — have measurable smell dysfunction.
“It will be very useful to use this window to analyze samples from people with conditions in which the nervous system has degeneration, such as Alzheimer’s disease,” Dr. Goldstein said.
“Alzheimer’s is of particular interest, since these patients lose their sense of smell quite early in the disease process, and we have few treatments for Alzheimer’s disease.”
“So, it may make sense to look carefully at regions of the olfactory system in these patients.”
“While we weren’t able to observe the neurons being made because of the nature of human samples, the molecular makeup of the immature neurons in the sample provides strong evidence that they were made in the nose during adulthood,” said Professor Hiroaki Matsunami, co-author of the study.
“Because the nose is exposed to the external environment, it might be possible we could one day collect these neuronal stem cells from patients and use them to treat their own brain disorders. It is not outside of the realm of possibility.”
The research was published in the journal Nature Neuroscience.
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M.A. Durante et al. 2020. Single-cell analysis of olfactory neurogenesis and differentiation in adult humans. Nat Neurosci 23, 323-326; doi: 10.1038/s41593-020-0587-9
