# Understanding spatial representations in rat orbitofrontal cortex

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA LOS ANGELES · 2024 · $465,625

## Abstract

Project summary
Growing evidence suggests that adaptive value representations in the brain are critical to flexible decision making. Inflexible
decisions are a hallmark of a range of neuropsychiatric disorders. Thus, understanding the typical neural substrates of value
representation may provide critical insights into the patterns of disordered decisions that characterize pathological
conditions. Convergent evidence over the past decades points to the orbitofrontal cortex (OFC) as a critical locus for value
representation and adaptive decisions. Evidence for neural encoding of the value of choice options is abundant, but it is less
well appreciated that such representations are also intertwined with spatial information the reflects the location where the
outcomes in question will be delivered. The utility—if any—of these pervasive OFC spatial representations is unknown.
This is at least partly due to the fact that most studies of OFC’s role in decision making involve subjects that make their
choices with minimal, if any, movement. We hypothesize that OFC spatial representations are a neural substrate for spatial
credit assignment, the process by which organisms learn to associate locations with the value of outcomes those locations
predict. Drawing inspiration from decision problems that foraging animals face in natural settings, we developed two new
behavioral tasks for rats that require spatial credit assignment. In the patch-leaving task rats shuttle between two foraging
patches where food pellets are delivered at different rates. The longer rats remain in one foraging patch, the lower the rate
of reward becomes. Switching between patches resets the reward rate to its maximal level, but incurs a time penalty in the
form of delay, during which food is not available. Adaptive decision making requires rats to associate information about
reward rate with each patch. In the value-map task, rats are trained to approach visual stimuli projected on to the floor of an
open-field arena, and are reinforced probabilistically for successfully completing trials. Reward probability is determined
by an uncued underlying probability map with localized regions where reward is more or less likely to be delivered.
Choosing correctly on choice trials requires learning the underlying probability structure of the task, and attributing higher
or lower value to locations in the arena with increased or decreased reward probability. Preliminary data demonstrate that
rats successfully perform both of these tasks. Neural recordings in lateral OFC identified two classes of spatially-responsive
neuron, one of which encodes space coarsely, over a large scale, and the other of which encodes space over a much finer
scale exhibiting discrete firing fields at particular locations. We hypothesize that these spatial cells are recruited to represent
value over large spatial scales (as required by the patch-leaving task) or finer spatial scales (as required by the value-map
task). C...

## Key facts

- **NIH application ID:** 10943613
- **Project number:** 1R01MH137276-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA LOS ANGELES
- **Principal Investigator:** Andrew M Wikenheiser
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $465,625
- **Award type:** 1
- **Project period:** 2024-08-15 → 2029-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10943613

## Citation

> US National Institutes of Health, RePORTER application 10943613, Understanding spatial representations in rat orbitofrontal cortex (1R01MH137276-01). Retrieved via AI Analytics 2026-06-12 from https://api.ai-analytics.org/grant/nih/10943613. Licensed CC0.

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