# Lightly Salted: An Optogenetic Approach to Uncover the Role of Type I Cells in Salt Taste Transduction

> **NIH NIH R21** · EASTERN MICHIGAN UNIVERSITY · 2020 · $144,086

## Abstract

Sodium (Na+) is an essential nutrient, but humans consume this nutrient in excess which
increases the risk of hypertension and stroke. It is currently unknown which cell type within taste
buds is responsible for Na+-taste transduction. Here, an optogenetic approach is used to
determine whether Type I cells within taste buds are responsible for Na+ taste transduced
through epithelial sodium channels (ENaCs). Optogenetic manipulation of Type I taste-bud cells
allows for selective perturbation of taste-bud circuity with an unprecedented level of precision—
unmatched by conventional pharmacology—and serves as a valuable tool for unraveling the
enigma of the taste of Na+. This project will test two hypotheses. 1) Optogenetic activation (via
Channelrhodopsin-2; ChR2) of Type I cells in fungiform-taste buds activates NaCl-best neurons
in the mouse Nucleus Tractus Solitarius (NTS), located in the medulla. 2) Optogenetic activation
(via ChR2) of Type I cells in fungiform taste buds elicits Na+ taste and drives Na+ appetite in Na+
deprived mice. Knowledge obtained from these investigations will provide the field with much
needed information about the role of Type I cells in taste function, and could provide a target for
pharmacological manipulation of taste circuitry to enhance salt taste, thereby decreasing Na+
intake. Such discoveries would have a positive impact on human health and disease afflicted by
excess Na+ consumption.

## Key facts

- **NIH application ID:** 9867718
- **Project number:** 5R21DC016990-03
- **Recipient organization:** EASTERN MICHIGAN UNIVERSITY
- **Principal Investigator:** Joseph Michael Breza
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $144,086
- **Award type:** 5
- **Project period:** 2018-03-22 → 2022-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9867718

## Citation

> US National Institutes of Health, RePORTER application 9867718, Lightly Salted: An Optogenetic Approach to Uncover the Role of Type I Cells in Salt Taste Transduction (5R21DC016990-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9867718. Licensed CC0.

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