# Untangling dopamine and glutamate neuron function in the VTA

> **NIH NIH R01** · UNIVERSITY OF COLORADO · 2024 · $664,061

## Abstract

Project Summary / Abstract
Ventral tegmental area (VTA) dopamine neurons are essential for associative learning of reward and aversion-
related cues, updating learned associations by prediction errors, as well as supporting a value of rewarding
and aversive outcomes. While it is well established that VTA dopamine neurons show heterogenous signaling
patterns related to these motivationally-relevant events, as well as express diverse molecular characteristics,
our understanding of how dopaminergic molecular heterogeneity contributes to VTA dopamine neuron
functions are unclear. A primary distinction between subtypes of VTA dopamine neurons is whether they
release dopamine alone or co-release dopamine with glutamate. We propose to test the hypothesis that VTA
dopamine neuron signaling patterns and roles in motivated behavior are genetically-determined by whether
they co-release dopamine with glutamate or they release dopamine without glutamate. In AIM 1, we will
determine the neuronal activity signaling patterns of VTA glutamate-dopamine co-releasing neurons,
nonglutamate-dopamine neurons, or glutamate-only neurons that do not co-release GABA or dopamine, in a
variety of reward and aversion-based motivated behavior tasks involving associative learning, outcome
prediction and errors, and outcome values. In AIM 2, we will causally determine the roles of these same
neurons in reward and aversion-based motivated behavior tasks involving associative learning, outcome
prediction, reward, and aversion. Finally in AIM 3, we will causally determine the roles of dopamine and/or
glutamate release from these distinct VTA neuronal phenotypes in reward and aversion-based tasks involving
associative and nonassociative learning as well as other motivationally-relevant behaviors. Together these
studies will comprehensively identify how the molecular heterogeneity of the midbrain dopamine system
contributes to associative learning and motivated behaviors.

## Key facts

- **NIH application ID:** 10943654
- **Project number:** 1R01MH137472-01
- **Recipient organization:** UNIVERSITY OF COLORADO
- **Principal Investigator:** David H Root
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $664,061
- **Award type:** 1
- **Project period:** 2024-07-03 → 2029-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10943654

## Citation

> US National Institutes of Health, RePORTER application 10943654, Untangling dopamine and glutamate neuron function in the VTA (1R01MH137472-01). Retrieved via AI Analytics 2026-06-02 from https://api.ai-analytics.org/grant/nih/10943654. Licensed CC0.

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