# The olfactory stimulation-dependent birth of neurons that express specific odorant receptors

> **NIH NIH R01** · UNIVERSITY OF COLORADO DENVER · 2024 · $435,684

## Abstract

Project Summary/Abstract
The olfactory epithelium is one of three major regions within the mammalian nervous system where new neurons are
added throughout life. In humans, a failure to maintain olfactory sensory neurogenesis is associated with olfactory
dysfunction, which afflicts an estimated 12.4 percent of adults in the U.S. and can adversely affect health and quality
of life. A key barrier to treating olfactory dysfunction is our incomplete understanding of how persistent olfactory
sensory neurogenesis is regulated and maintained. A related deficiency lies in our understanding of why neurogenesis
persists within the olfactory epithelium. Life-long olfactory sensory neurogenesis is presumed to function solely to
replace damaged olfactory sensory neurons. However, work from our laboratory has demonstrated that the birthrates
of neurons that express a fraction of odorant receptors are accelerated upon stimulation by specific odors, leading to
the central hypothesis of this proposal: that persistent neurogenesis within the olfactory epithelium serves, in part, an
adaptive function. Our results are not readily explained by the current model of olfactory sensory neurogenesis, which
predicts that the relative birthrates of neurons expressing each of the hundreds of different receptor genes encoded in
the genome are determined stochastically by a process in which each post-mitotic neural precursor randomly ‘chooses’
a single odorant receptor gene for expression. Accordingly, the relative birthrates of distinct olfactory sensory neuron
‘subtypes’ are expected to be impervious to olfactory experience. The overall objective of this proposal is to determine
how odor stimulation selectively accelerates the birthrates of specific olfactory sensory neuron subtypes. Our working
model is that a fraction of subtypes have a special capacity, upon stimulation by odors with potential salience, to
amplify themselves by selectively promoting the proliferation of mitotic neural progenitors that are of the same lineage
and predisposed toward the same subtype fate. This model will be tested through three specific aims. Aim 1 will test
the hypothesis that olfactory stimuli that selectively promote the neurogenesis of specific neuron subtypes are discrete,
salient odors that selectively stimulate those subtypes. This will be tested by identifying, via a selective single-cell
sequencing-based approach, the scope of neuron subtypes whose birthrates are accelerated by sex-specific odors. Aim
2 will test the hypothesis that some mitotic neural progenitors are predisposed toward specific odorant receptor fates
that can be selectively amplified via cell proliferation. This will be tested by mapping the subtype fates of individual
progenitors using genetic barcoding and in situ sequencing strategies. Aim 3 will test the hypothesis that mature olfac-
tory sensory neurons of specific subtypes have a special capacity to promote the proliferation of progenitors within the
same lin...

## Key facts

- **NIH application ID:** 10879105
- **Project number:** 5R01DC019936-02
- **Recipient organization:** UNIVERSITY OF COLORADO DENVER
- **Principal Investigator:** Stephen Santoro
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $435,684
- **Award type:** 5
- **Project period:** 2023-07-01 → 2028-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10879105

## Citation

> US National Institutes of Health, RePORTER application 10879105, The olfactory stimulation-dependent birth of neurons that express specific odorant receptors (5R01DC019936-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10879105. Licensed CC0.

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