# Neuronal and Dopaminergic Contributions to Dissimilar Evoked Hemodynamic Responses in the Striatum

> **NIH NIH F32** · UNIV OF NORTH CAROLINA CHAPEL HILL · 2020 · $72,446

## Abstract

PROJECT SUMMARY
Blood oxygenation level-dependent functional magnetic resonance imaging (BOLD fMRI) is a non-invasive
imaging technique that infers the presence of increased brain activity from localized increases in oxygenated
hemoglobin. Interpreting BOLD data largely depends on the assumption that neuronal firing and increased blood
flow directly correlate across the brain in a process known as neurovascular coupling. However, the influence of
vasoactive neurotransmitters on BOLD signals have been largely ignored in interpreting brain functionality, such
that current interpretations are incomplete. This is especially crucial to understand in the striatum, a brain region
heavily involved in reward prediction and drug addiction, where coupling is not conserved. The vasoactive
neurotransmitter dopamine is abundant throughout the striatum, yet its modulatory role over striatal
hemodynamics is poorly understood. This proposed work seeks to understand how dopamine and striatal
neurons contribute to both positive and negative BOLD responses to direct brain stimulation.
By using a cutting-edge suite of techniques, we will selectively stimulate dopamine neurons or striatal neurons
with optogenetics and systematically eliminate neuronal or neurotransmitter receptor components to investigate
their contribution to the hemodynamic response. In response to a stimulus, fast-scan cyclic voltammetry will
detect local dopamine and oxygen changes at an implantable microelectrode, and fMRI will be used
simultaneously to monitor oxygen changes across the brain. Pharmacology and chemogenetics will be used to
selectively activate or inhibit receptors and cell types. These experiments will expand our ability to interpret fMRI
data accurately by establishing and quantifying both neuronal and neurotransmitter contributions to the striatal
hemodynamic response.

## Key facts

- **NIH application ID:** 9851943
- **Project number:** 5F32MH115439-03
- **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL
- **Principal Investigator:** Lindsay Walton
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $72,446
- **Award type:** 5
- **Project period:** 2018-02-01 → 2021-08-23

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9851943

## Citation

> US National Institutes of Health, RePORTER application 9851943, Neuronal and Dopaminergic Contributions to Dissimilar Evoked Hemodynamic Responses in the Striatum (5F32MH115439-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9851943. Licensed CC0.

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