# Dissecting the neural circuit mechanisms that generate dopamine neuron activity

> **NIH NIH R01** · HARVARD UNIVERSITY · 2024 · $656,073

## Abstract

Project Summary
The midbrain dopamine system plays a crucial role in various brain functions such as learning, motivation, and
movement, and its dysregulation has been linked to various disorders such as addiction, mood disorders and
Parkinson’s disease. A significant amount of evidence suggests that the activity of dopamine neurons in the
ventral tegmental area (VTA) resembles a temporal difference (TD) reward prediction error (RPE) signal, which
is the discrepancy between predicted and actual rewards, particularly, in those dopamine neurons projecting to
the ventral striatum (VS). However, how the activity of dopamine neurons, particularly the RPE-related activity,
is generated remains not fully understood. By combining new molecular, genetic, and electrophysiological
tools, this project aims to uncover how neural circuits compute RPE-like responses. Aim 1 will examine the
roles of glutamate inputs to dopamine neurons in the generation of dopamine responses. The overall pattern of
glutamate inputs to dopamine neurons will be assessed using genetically-encoded glutamate sensors. The
hypotheses to be tested is that glutamate and GABA inputs to dopamine neurons act synergistically to produce
dopamine RPE signals, but compete to shape dopamine responses to aversive events. Aim 2 will create
anatomical and functional maps of cell type-specific presynaptic neurons to dopamine neurons. Input neurons
for dopamine neurons are distributed across many brain regions throughout the brain. Understanding the
specific information transmitted from each region is crucial to comprehend how dopamine responses are
generated. A novel method using a modified rabies virus will be applied to perform cell type-specific labeling of
input neurons to projection-specific dopamine neurons. Using these tools, an anatomical map of glutamate and
GABA inputs to dopamine neurons projecting to the VS will be created. Then electrophysiology and fiber
photometry will be used to characterize functional activities of these input neurons during behavior. Their roles
in the regulation of dopamine activity will then be tested by manipulating the activity of the major inputs. Aim 3
aims to elucidate the mechanism of dopamine-dependent incremental development of dopamine cue
responses. Optogenetically-induced local dopamine release will be paired with sensory cues to elucidate the
mechanisms underlying the development of dopamine cue responses. The preliminary results have indicated
that local dopamine release in the VS, but not in the dorsal striatum, causes the development of dopamine cue
responses broadly across the striatum. The hypothesis to be tested is that dopamine responses as well as
value-related activity in the striatum gradually shift in time between cue and optogenetic dopamine activation,
as predicted by TD learning models. Further, how this learning modulates the activity of neurons in VS and
other brain regions will be examined. This Aim will clarify the neural mechanism t...

## Key facts

- **NIH application ID:** 10792755
- **Project number:** 1R01DA059751-01
- **Recipient organization:** HARVARD UNIVERSITY
- **Principal Investigator:** Naoshige Uchida
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $656,073
- **Award type:** 1
- **Project period:** 2024-07-15 → 2029-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10792755

## Citation

> US National Institutes of Health, RePORTER application 10792755, Dissecting the neural circuit mechanisms that generate dopamine neuron activity (1R01DA059751-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10792755. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*