# Dopamine signaling and function during spatial navigation

> **NIH NIH U19** · HARVARD MEDICAL SCHOOL · 2020 · $437,562

## Abstract

Project abstract
Dopamine plays important roles in learning and motivation. It has been thought that dopamine neurons (DANs)
signal reward prediction errors (RPEs) but this idea has been challenged by some recent findings. For one,
some studies found that dopamine concentration in the ventral striatum slowly ramps up on the timescale of
several seconds during goal-directed navigation, and it was proposed that these slow-timescale dopamine
fluctuations may encode Value instead of RPEs. Because RPEs (as defined by temporal difference error in
reinforcement learning theories) are approximately the temporal derivative of Value, these proposals are
incompatible with the RPE hypothesis. As discussed in Project 1, a theory predicts that ramping dopamine can
be explained by RPEs in certain conditions. This project (Project 3) will put this idea into experimental tests. A
set of experimental tests will be developed using virtual reality in head-fixed mice (Aim 1). Specifically, RPE
and Value accounts will be dissociated by teleporting the animal to a new location associated with a different
Value, or by changing the speed of the scene movement. Aim 2 will test the hypothesize that an explicit cue
that indicates the proximity of reward is sufficient to induce a dopamine ramp in non-navigational contexts.
Furthermore, by manipulating stimulus parameters, Aim 2 also aims at determining under what task conditions
dopamine ramps or not. Aim 3 will experimentally manipulate DAN activity, and examine the function of slowly-
fluctuating dopamine signals in the regulation of the activity of spiny projection neurons in the striatum and
behaviors in goal-directed navigation.

## Key facts

- **NIH application ID:** 9993582
- **Project number:** 5U19NS113201-02
- **Recipient organization:** HARVARD MEDICAL SCHOOL
- **Principal Investigator:** Naoshige Uchida
- **Activity code:** U19 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $437,562
- **Award type:** 5
- **Project period:** 2019-08-15 → 2024-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9993582

## Citation

> US National Institutes of Health, RePORTER application 9993582, Dopamine signaling and function during spatial navigation (5U19NS113201-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9993582. Licensed CC0.

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