# Dopaminergic modulation of the fly grooming sequence

> **NIH NIH R21** · UNIVERSITY OF CALIFORNIA SANTA BARBARA · 2020 · $427,261

## Abstract

Project Summary
Dopamine is a critical neurotransmitter and neuromodulator that governs essential neural
circuits and behaviors. It has been implicated in human motor syndromes from Parkinson’s
Disease to Obsessive-Compulsive Disorder, but its mechanism of action is not fully understood.
Alterations in dopamine signaling affect fly grooming behavior, which is also a complex motor
sequence. This discovery opens the door to using the exceptional experimental advantages of
this organism to address fundamental open questions. The ability to manipulate small numbers
of dopaminergic neurons, measure behavioral consequences, and visualize neural connectivity
and activity make fly grooming an excellent model to better understand the action of dopamine
at molecular, subcellular, cellular, circuit, and organismal levels. We propose behavioral
experiments to determine how dopamine affects the fine structure of an innate, modular motor
sequence, where it may enable flexibility based on internal state and changing sensory stimuli.
We also propose anatomical characterization of dopaminergic neurons in the ventral nerve cord
and their synaptic partners to identify circuit motifs that modify sensory neuron activity. These
experiments test the hypothesis that dopamine sustains neural activity in mechanosensory
bristle neurons, leading to useful behavioral persistence during grooming. This mechanism may
explain more generally how dopamine contributes to motor control and action sequence
organization.

## Key facts

- **NIH application ID:** 9873426
- **Project number:** 1R21NS114618-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA SANTA BARBARA
- **Principal Investigator:** JULIE H SIMPSON
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $427,261
- **Award type:** 1
- **Project period:** 2019-12-01 → 2022-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9873426

## Citation

> US National Institutes of Health, RePORTER application 9873426, Dopaminergic modulation of the fly grooming sequence (1R21NS114618-01). Retrieved via AI Analytics 2026-06-11 from https://api.ai-analytics.org/grant/nih/9873426. Licensed CC0.

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