# The efferent synapse in enteroendocrine cells

> **NIH NIH R21** · DUKE UNIVERSITY · 2020 · $201,250

## Abstract

ABSTRACT
Today, there is a fascination with gut-to-brain sensory transduction. Nutrients and bacteria are known to
modulate behaviors. However, how the brain modulates gastrointestinal sensory function is unknown.
Several behavioral disorders, such as those related to stress and appetite, have been linked with
altered visceral function. The pillars of sensory transduction in the gut are the neurons that innervate
the mucosa and the enteroendocrine cells — epithelial cells that face the lumen. When stimulated by
nutrients, or bacteria, they fire action potentials. We recently discovered that these cells synapse with
the vagus nerve to transduce nutrient stimuli to the brain in milliseconds. They do so using glutamate
as a neurotransmitter. Recent studies have also shown that a subset of enteroendocrine cells that
secrete serotonin are activated by the sympathetic neurotransmitter, norepinephrine. Our preliminary
data show that these cells also receive synaptic inputs from peripheral neurons of the spinal cord.
Therefore, we hypothesize that spinal neurons use norepinephrine as an efferent neurotransmitter to
modulate enteroendocrine cell sensory function. With the support of this NIH R21 research project, our
goal is to dissect this neural circuit by 1) defining the efferent synapse both in vivo and in vitro; and 2)
establishing norepinephrine as an efferent neuron-to-enteroendocrine cell synaptic neurotransmitter.
This project will set the neural basis for understanding how brain function and behaviors alter visceral
sensory function.

## Key facts

- **NIH application ID:** 10018637
- **Project number:** 5R21AT010818-02
- **Recipient organization:** DUKE UNIVERSITY
- **Principal Investigator:** Diego V Bohorquez
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $201,250
- **Award type:** 5
- **Project period:** 2019-09-16 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10018637

## Citation

> US National Institutes of Health, RePORTER application 10018637, The efferent synapse in enteroendocrine cells (5R21AT010818-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10018637. Licensed CC0.

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