Summary: Why do we suddenly feel motivated when we walk into a familiar coffee shop or see a favorite restaurant sign? New research identifies a physical intersection in the brain where memory and desire meet, revealing how spatial maps and emotion-driven motivation combine to guide goal-directed behavior.
Researchers found that two distinct parts of the hippocampus—the dorsal hippocampus, involved in spatial memory and navigation, and the ventral hippocampus, tied to emotion and mood—converge onto the same neurons in the nucleus accumbens, the brain’s central reward hub. When these separate hippocampal pathways activate the same accumbens neurons simultaneously, their signals amplify one another, converting a neutral memory of a place into a strong, reward-seeking drive.
Key Facts
- Convergence Zone: Inputs from the dorsal and ventral hippocampus converge on individual neurons in the nucleus accumbens, overturning the view that these pathways act entirely separately.
- Synaptic Proximity: Synapses from the two hippocampal pathways often sit within a few microns of each other on the same dendritic branches, allowing rapid interaction.
- Amplified Response: When both inputs fire together, the combined electrical response in accumbens neurons is larger than the sum of each input alone, a heterosynaptic “multiplier” effect.
- Dual-Color Optogenetics: The team used red and blue light to independently stimulate the dorsal and ventral hippocampal inputs while recording responses in single accumbens neurons, revealing real-time integration of signals.
- Clinical Relevance: Understanding this integration sheds light on disorders of motivation—such as depression, anhedonia, and addiction—where the link between context and reward is disrupted or overamplified.
Source: University of Maryland
New findings from the University of Maryland, Baltimore County (UMBC) explain how hippocampal pathways combine with reward circuits to link places and contexts to motivation.
Published in the Journal of Neuroscience, the study shows that dorsal and ventral hippocampal inputs converge on the same medium spiny neurons in the ventromedial shell of the nucleus accumbens. This anatomical and functional convergence allows memory of “where” and the emotional value of “what feels good” to be integrated at the level of single neurons, shaping decisions such as why we choose to visit a familiar café or return to a location that once provided safety or food.
“This connection between the hippocampus and the nucleus accumbens is where the brain’s map of where to go meets a sense of why it’s worth going,” says senior author Tara LeGates, assistant professor in UMBC’s Department of Biological Sciences. The results challenge the long-held assumption that dorsal and ventral hippocampal pathways to the accumbens operate independently.
LeGates and colleagues emphasize that a single neuron can integrate inputs from distinct brain regions, and uncovering how this integration occurs is essential for understanding the neural basis of goal-directed actions. Though the experiments were performed in mice, the conserved anatomy across mammals suggests the mechanism likely applies broadly, including in humans.
A close-up on convergence
The researchers combined optogenetics, electrophysiology, and high-resolution microscopy to identify neurons in the nucleus accumbens that receive direct inputs from both the dorsal and ventral hippocampus. Using dual-color optogenetic stimulation, they activated each pathway independently with different wavelengths of light while recording electrical responses in single accumbens neurons.
Microscopy at UMBC’s imaging facility produced ultra-thin digital slices and three-dimensional reconstructions of dendritic branches, confirming that terminals from both hippocampal pathways sit in close proximity—often within a couple of microns—on the same dendritic segments. That anatomical arrangement enables fast, heterosynaptic interactions, so simultaneous activation of both inputs produces a potentiated response greater than either input alone.
First author Ashley Copenhaver led many of the recordings and imaging efforts, mentoring undergraduate team members. She describes the dual-color optogenetic experiments—literally shining tiny beams of red and blue light onto brain tissue while recording the resulting electrical activity—as a vivid demonstration of signal integration at the cellular level.
From cells to behavior
Understanding how individual neurons integrate distinct inputs is critical for linking cellular mechanisms to complex behaviors. According to LeGates, the newly documented convergence suggests that hippocampal signals about location and emotional value interact more than previously appreciated, which could change how researchers study motivation and learning.
Such convergence helps animals form associations between rewarding outcomes and the contexts in which they occur, aiding survival by guiding return to places where food, shelter, or social interaction were rewarding. Similar integrative strategies have been observed in other brain regions involved in emotional learning, indicating this may be a general neural motif for linking context to feeling and action.
LeGates’ lab is extending this work to examine how stress and substances—ranging from natural rewards like food to medications and illicit drugs—affect these hippocampus-to-accumbens connections. The goal is to better understand how these circuits change in conditions that alter motivation and to inform more targeted interventions for mental health disorders.
Next steps for the team include recording activity from these specially connected neurons during real behaviors to directly connect the observed cellular crosstalk to actions in freely moving animals.
By uncovering this level of cooperation between hippocampal pathways, the study advances our understanding of how memory and motivation are woven together in the brain—a fundamental process shaping everyday choices and survival behaviors.
Key Questions Answered:
A: Yes. The dorsal hippocampus recognizes the location or visual cue, while the ventral hippocampus evokes the emotional value associated with that place. When both signals converge on the same accumbens neurons, they together strengthen the motivational drive to seek the reward.
A: Disrupted communication could underlie symptoms such as anhedonia in depression, where a person remembers places or activities but lacks the motivational pull to engage with them.
A: The experiments were carried out in mice, but the hippocampus and nucleus accumbens are anatomically conserved across mammals, suggesting this integration is likely a common neural strategy for linking context and emotional value.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- The journal paper was reviewed in full by editorial staff.
- Additional context was added by the editorial team to clarify technical findings for a general audience.
About this neuroscience research news
Author: Sarah Hansen
Source: University of Maryland
Contact: Sarah Hansen, University of Maryland
Image: Image credited to Neuroscience News
Original Research: Closed access. “Heterosynaptic Interactions between the Dorsal and Ventral Hippocampus in Individual Medium Spiny Neurons of the Nucleus Accumbens Ventromedial Shell” by Ashley E. Copenhaver et al., published in the Journal of Neuroscience. DOI: 10.1523/JNEUROSCI.1225-25.2026
Abstract
Heterosynaptic Interactions between the Dorsal and Ventral Hippocampus in Individual Medium Spiny Neurons of the Nucleus Accumbens Ventromedial Shell
Forming learned associations between rewarding stimuli and the contexts where those rewards occur is essential for adaptive behavior. Hippocampal input to the nucleus accumbens supplies environmental context that supports reward processing and goal-directed actions. These inputs arise from both the dorsal hippocampus (dHipp), associated with spatial memory, and the ventral hippocampus (vHipp), linked to affect and motivation. Previously treated as distinct pathways, dHipp and vHipp terminals are shown here to overlap in the nucleus accumbens, prompting a reevaluation of their functional independence.
Using optogenetics, electrophysiology, transsynaptic labeling, and high-resolution imaging in male and female mice, the authors identified a subpopulation of accumbens neurons receiving convergent inputs from both hippocampal regions. Close apposition of dHipp and vHipp synapses along dendritic branches supports fast heterosynaptic interactions, and simultaneous stimulation of both inputs produced potentiation beyond what either input produced alone. Comparison of measured and theoretical response rates suggests some interactions may be presynaptic.
Together, these results demonstrate that dHipp and vHipp inputs converge on a subset of nucleus accumbens neurons with synaptic arrangements that enable rapid integration, highlighting how single neurons can combine distinct contextual and motivational signals to shape learning and behavior.