# Connectivity of periperal taste neurons

> **NIH NIH F31** · UNIVERSITY OF LOUISVILLE · 2021 · $8,119

## Abstract

Project Summary/Abstract
While the function of taste neurons (that connect taste receptor cells to the brain) has been well-
studied, almost nothing is known about individual taste neuron morphology or peripheral
connectivity. Specifically, it is unclear how many taste receptor cells provide input to a single
neuron or even if those receptor cells are all the same type. This lack of knowledge contributes
to our relatively poor understanding of peripheral taste coding mechanisms. This project will use
a combination of sparse cell genetic labeling and serial blockface scanning electron microscopy
(SBF-SEM) to 1) examine the number of taste receptor cells likely contacted by chorda tympani
neurons of differing complexity 2) determine if individual neurons contact receptor cells of the
same type or more than one type. I will accomplish these goals via three specific Aims. In Aim
1, I will determine if there are any structural motifs present at synapses or non-synaptic
structural connections using SBF-SEM, which can also be identified in 3-D confocal images of
sparsely labeled nerve fibers and taste receptor cells. The goal is to permit better interpretation
of the anatomical relationships between receptor cells and nerve fibers at the light level. In Aim
2, I will reconstruct separate fibers entering the taste bud using SBF-SEM, which will determine
the rules of connectivity of simply vs. sparsely branched fibers within the fungiform taste bud.
These data will be compared with the contacts identified, using image analysis software at the
light level between individual fibers entering the taste bud. In Aim 3, I will analyze the
morphology of whole chorda tympani nerve fibers, innervating anywhere from 1 to 7 taste buds,
and relate their branching complexity to the number and types of peripheral contacts made with
taste receptor cells. Together, these experiments will test the hypothesis that heavily branched
neurons contact many more taste receptor cells of multiple types, compared to simply branched
neurons which will contact only a few receptor cells of a single type. This project will be the first
to examine the peripheral connectivity of individual chorda tympani neurons, and may reveal an
anatomical substrate for the physiological finding that some neurons are narrowly tuned
(respond to one taste stimulus) whereas others are broadly tuned (respond to multiple taste
stimuli). Determining the peripheral connectivity of individual neurons will likely inform future
experiments designed to look at taste coding. These baseline data for the normal connectivity of
the peripheral taste system can be used to compare the potential disruption of connectivity that
may result from disease states or manipulations of molecular factors regulating the formation of
these connections.

## Key facts

- **NIH application ID:** 10378844
- **Project number:** 3F31DC017660-03S1
- **Recipient organization:** UNIVERSITY OF LOUISVILLE
- **Principal Investigator:** Lisa C Ohman
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $8,119
- **Award type:** 3
- **Project period:** 2018-09-01 → 2021-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10378844

## Citation

> US National Institutes of Health, RePORTER application 10378844, Connectivity of periperal taste neurons (3F31DC017660-03S1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10378844. Licensed CC0.

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