# Molecular signature of parafacial expiratory neurons

> **NIH NIH R21** · UNIVERSITY OF CONNECTICUT STORRS · 2023 · $442,750

## Abstract

PROJECT SUMMARY
A critical feature of the respiratory system is its ability to adapt to increased metabolic demand by recruitment of
expiratory muscles to facilitate alveolar ventilation, a process referred to as active expiration. Active expiration
is thought to be mediated by a cluster of neurons located in the lateral parafacial region (pFL). However, despite
this physiological significance, the identity of expiratory pFL neurons is not known and unique markers of these
cells have not been determined. To address this need, proposed experiments will determine the molecular
profile of expiratory pFL neurons and identify unique markers of this population that can be used to selectively
label and manipulate this population for detailed functional analysis. We will use RNA-seq to perform an
unbiased evaluation of transcript expression of neurons from the pFL region and a nearby respiratory center
called the retrotrapezoid nucleus (RTN). This analysis will focus on glutamatergic populations that are expected
to include expiratory pFL neurons and RTN neurons. We will use the known molecular profile of RTN neurons
as a touchstone for identification of unique pFL markers. To correlate gene expression with function, we will
characterize baseline activity and CO2/H+ sensitivity of putative expiratory parafacial neurons back-labelled from
an expiratory control center, and we will manually harvest these cells for targeted qPCR to identify common and
differentiating genes between RTN and pFL populations. Identifying the transcriptome of pFL neurons will
represent a major technical advance in the field of respiratory control as it would make possible the development
of targeting strategies to selectively manipulate this population. This work will also provide insight into the genetic
organization of neurons and circuits that control breathing, and in doing so help understand how these elements
are perturbed in disease.

## Key facts

- **NIH application ID:** 10750185
- **Project number:** 1R21NS134132-01
- **Recipient organization:** UNIVERSITY OF CONNECTICUT STORRS
- **Principal Investigator:** Daniel K Mulkey
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $442,750
- **Award type:** 1
- **Project period:** 2023-07-01 → 2026-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10750185

## Citation

> US National Institutes of Health, RePORTER application 10750185, Molecular signature of parafacial expiratory neurons (1R21NS134132-01). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10750185. Licensed CC0.

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