# The organizing principle of grouped olfactory receptor neurons

> **NIH NIH R21** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2021 · $237,000

## Abstract

PROJECT SUMMARY/ABSTRACT
The goal of this project is to determine the organizing principle underlying olfactory receptor neuron (ORN)
grouping in the antennal sensory hairs of Drosophila. For most sensory systems, neurons are arranged in an
ordered manner to form topographic representations of stimuli from the external world. Understanding the
organizing principle of such maps is critical for deciphering the nature of salient features that are extracted
from parallel inputs through lateral inhibition. However in olfaction, whether and how neurons are organized
into a sensory map remains largely unclear. In both rodents and flies, it is reported that neighboring glomeruli
do not necessarily respond to similar odorants. In the absence of a chemotopic map, what then is the
organizing principle for the olfactory system? To address this complex question, the research outlined here
leverages the powerful genetic toolkit and tractable olfactory system of Drosophila. The general hypothesis—
that ORNs are organized in the periphery based on the hedonic value of their detected odors to form a valence
map—will be tested via systematic behavioral assays with optogenetic or thermogenetic activation of select
receptor neurons. The proposal’s first aim is to determine the generality of the observation that in the same
sensory hair, compartmentalized ORNs mediate opposing behavior—with attraction elicited by activation of the
large-spike ORN(s) and aversion by the small-spike neighbor(s). The remaining aims propose to examine this
organizing principle in sensory hairs implicated in regulating female egg-laying (Aim 2) or male courtship
behavior (Aim 3). Successful execution of the proposal will likely bridge a longstanding knowledge gap in
sensory biology by revealing, for the first time, olfactory maps within a complex organism.

## Key facts

- **NIH application ID:** 10197096
- **Project number:** 5R21DC018912-02
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** Chih-Ying Su
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $237,000
- **Award type:** 5
- **Project period:** 2020-07-01 → 2023-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10197096

## Citation

> US National Institutes of Health, RePORTER application 10197096, The organizing principle of grouped olfactory receptor neurons (5R21DC018912-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10197096. Licensed CC0.

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