# Dopamine Mediated Control of Retinal Vascular Integrity

> **NIH NIH R01** · BAYLOR COLLEGE OF MEDICINE · 2024 · $612,894

## Abstract

PROJECT SUMMARY
Dopamine is a neuromodulator with a critical role in vascular diseases of the eye. Our recent studies show that
dopamine can directly signal to the vasculature via dopamine receptors and act as a developmental timing cue
for hyaloid vascular regression through its regulation of VEGF. Here, we now extend these studies to the retina
vasculature. Our preliminary data show that increasing dopamine signaling in the developing retina decreases
vascular density, while decreasing dopamine causes vasculature overgrowth. We further identify retinal
ganglion cells as novel dopamine producing cells and show that they directly modulate vascular growth. This is
an important finding because dopamine was previously thought to be produced only by a subset of amacrine
cells. To understand the mechanisms by which RGCs become dopaminergic and the vascular pathways
through which they signal, we propose three experimental aims. We test whether dopamine has a direct (Aim
1) or indirect (Aim 2) effect on retinal vascular cells using vascular and neuron cell-specific strategies to
remove dopamine receptors. We also ask whether dopamine and VEGFA function in trophic feedback within
the retina to establish causation. In Aim 3, we determine the neuronal mechanisms by which RGC-derived
dopamine modulates the vasculature through examination of the temporal and genetic pathways that regulate
these unique cells. Identification of a dopaminergic-RGC dependent mechanism for modifying vasculature
development and homeostasis is unexpected, so when completed this work will change the way we
understand dopamine signaling and its distinct cellular roles. This work will also guide future efforts aimed at
developing new therapeutic options to target retina vasculopathies.

## Key facts

- **NIH application ID:** 10864807
- **Project number:** 5R01EY032566-03
- **Recipient organization:** BAYLOR COLLEGE OF MEDICINE
- **Principal Investigator:** Melanie A Samuel
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $612,894
- **Award type:** 5
- **Project period:** 2022-09-30 → 2027-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10864807

## Citation

> US National Institutes of Health, RePORTER application 10864807, Dopamine Mediated Control of Retinal Vascular Integrity (5R01EY032566-03). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10864807. Licensed CC0.

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