Summary: For decades, dopamine has been described mainly as the brain’s “reward” chemical—released when we encounter something valuable or pleasurable. New research from a Boston University-led team reveals an additional, distinct role: dopamine also functions as a real-time guidance system that signals whether an organism is moving toward or away from a goal.
Using visually cued environments and advanced optical recording in mice, the researchers identified a second dopamine signal that behaves like an internal GPS. This signal encodes moment-to-moment “trajectory errors,” reporting whether current direction and speed are helping the animal approach its target or causing it to deviate.
Key Facts
- The Trajectory Signal: Distinct from the classic reward-related dopamine response, this trajectory signal indicates whether ongoing motion is aligned with an optimal path. It increases when movement is headed toward the goal and decreases when the animal veers off course.
- Localized in the Striatum: These guidance signals are represented across the striatum, a key part of the basal ganglia. New wide-field optical imaging revealed overlapping but spatially distinct gradients for reward value and guidance signals.
- Independent of Reward: The guidance signal operates separately from dopamine’s value encoding. It draws on different sensory and motor inputs than the reward-related dopamine response, allowing simultaneous but distinct influences on behavior.
- Scales with Speed: The trajectory error signal scales with the animal’s movement speed, providing a high-fidelity, real-time update suitable for rapid course corrections—analogous to using familiar landmarks while driving to confirm you are on the right route.
- Clinical Relevance: Recognizing a guidance role for dopamine could reshape how we think about and treat disorders marked by disrupted goal-directed behavior, including Parkinson’s disease, ADHD, addiction, and obsessive-compulsive disorder.
Source: Boston University
A Boston University-led research team has identified a dopamine signal that reports whether an animal is moving toward or away from a goal, offering new insight into how the brain uses visual information to steer behavior.
Published in Nature, the study tracked mice navigating visually cued environments and showed that cue-evoked dopamine activity in the striatum encodes bidirectional trajectory errors. These signals reflect the relationship between the animal’s current speed and direction and the optimal trajectory to a goal. Importantly, the guidance signals are separable from simultaneous dopamine increases that reflect learned cue value, indicating distinct functional streams within the same neuromodulatory system.
The results clarify how environmental cues are transformed into online control signals that steer behavior. By separating motivational value from navigational guidance, the brain can both motivate action and refine movement in real time.
“This discovery reveals that dopamine isn’t just about how valuable something is,” said Mark Howe, assistant professor of psychological and brain sciences at Boston University. “It’s also about whether you’re headed the right way. It’s a guidance signal, one that tells the brain to keep going or to correct course.”
A New View of Dopamine’s Role
Dopamine’s reputation as a reward signal is well established, but these findings highlight a second, functionally distinct signal driven by visual and sensorimotor inputs. The trajectory error signal grows when movements align with a goal and falls when movements diverge, providing continuous feedback that can support rapid corrections and precise navigation.
Seeing the Brain in Greater Detail
The team developed an optical measurement approach capable of resolving dopamine signals across many areas of the striatum simultaneously. Mapping these responses revealed overlapping but orthogonal gradients for value and trajectory error, as well as different temporal dynamics. This anatomical and temporal separation helps the brain multiplex motivational and guidance information without conflating the two.
Future Work
The researchers are now manipulating these distinct dopamine signals to test their causal roles in learning and the online control of decisions. They are also studying how these signals influence downstream circuits that ultimately shape behavior. Key questions remain: How do guidance and value signals translate into changes in movement? Are both signals essential for learning, routine navigation, or both?
Funding: This work was supported by the Klingenstein-Simons Foundation fellowship, the Whitehall Foundation Fellowship, the National Institute of Mental Health, and the NIH Jointly Sponsored Predoctoral Training Program in the Neurosciences.
Complete details on authorship, methodology, limitations, funders, and any conflicts of interest are available in the published paper.
Key Questions Answered:
A: Dopamine still encodes reward-related information, but it also carries a separate guidance signal. Think of value as the destination and trajectory as the turn-by-turn directions: motivation and navigation work together but are signaled independently.
A: These conditions involve disrupted dopamine signaling. If the guidance component of dopamine is reduced or noisy, an individual may be motivated to complete a task but lack the continuous feedback needed to stay on course, making sustained, goal-directed behavior more difficult.
A: This study used mice and advanced optical sensors, but the striatum is evolutionarily conserved across mammals. The findings suggest similar mechanisms may operate in humans when navigating environments, from walking through a crowded room to following a familiar driving route.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- The journal paper was reviewed in full.
- Additional context was provided by staff editors.
About this neuroscience research news
Author: Jennifer Rosenberg
Source: Boston University
Contact: Jennifer Rosenberg – Boston University
Image: Image credited to Neuroscience News
Original Research: Closed access.
“Striatum-wide dopamine encodes trajectory errors separated from value” by Eleanor H. Brown, Yihan Zi, Mai-Anh Vu, Safa Bouabid, Jack Lindsey, Chinyere Godfrey-Nwachukwu, Aaquib Attarwala, Ashok Litwin-Kumar, Brian DePasquale & Mark W. Howe. Nature
DOI: 10.1038/s41586-025-10083-1
Abstract
Striatum-wide dopamine encodes trajectory errors separated from value
Goal-directed navigation requires animals to continuously evaluate whether their current direction and speed of travel relative to landmarks are bringing them closer to or farther from a goal. While striatal dopamine release signals the reward-predictive value of cues and likely supports motivation, it has been unclear how dopamine might also represent an animal’s ongoing trajectory for behavioral guidance.
This study demonstrates that cue-evoked dopamine release across the striatum encodes bidirectional trajectory errors that reflect how the speed and direction of movement relate to optimal goal trajectories. These trajectory error signals can be driven by locomotor feedback or by visual flow, and they operate independently from simultaneous dopamine responses reflecting learned cue value.
Both trajectory error and cue-value encoding can be reproduced by a reinforcement learning framework that integrates mixed sensorimotor inputs, yet each signal has distinct state-space requirements. Multifiber array measurements across the striatum revealed overlapping but temporally and anatomically separable representations of trajectory error and cue value, showing how the brain multiplexes distinct dopamine signals for motivation and guidance to support goal-directed behavior.