Subpopulations of neurons in lOFC encode previous and current rewards at time of choice
Abstract
Studies of neural dynamics in lateral orbitofrontal cortex (lOFC) have shown that subsets of neurons that encode distinct aspects of behavior, such as value,may project to common downstreamtargets. However, it is unclear whether reward history, which may subserve lOFC's well-documented role in learning, is represented by functional subpopulations in lOFC. Previously, we analyzed neural recordings from rats performing a value-based decision-making task, and we documented trial-by-trial learning that required lOFC (Constantinople et al., 2019). Here we characterize functional subpopulations of lOFC neurons during behavior, including their encoding of task variables. We found five distinct clusters of lOFC neurons, either based on clustering of their trial-averaged peristimulus time histograms (PSTHs), or a feature space defined by their average conditional firing rates aligned to different task variables. We observed weak encoding of reward attributes, but stronger encoding of reward history, the animal's left or right choice, and reward receipt across all clusters. Only one cluster, however, encoded the animal's reward history at the time shortly preceding the choice, suggesting a possible role in integrating previous and current trial outcomes at the time of choice. This cluster also exhibits qualitatively similar responses to identified corticostriatal projection neurons in a recent study (Hirokawa et al., 2019), and suggests a possible role for subpopulations of lOFC neurons in mediating trial-by-trial learning.
Data availability
Physiology, behavior, GLM statistical modeling, and clustering results source data are publicly available on Zenodo. https://doi.org/10.5281/zenodo.5592702.Code for the GLM model fit, clustering, and all subsequent analysis will also be provided publicly via Github atgithub.com/constantinoplelab/published/
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Subpopulations of neurons in lOFC encode previous and current rewards at time of choiceZenodo, doi:10.5281/zenodo.5592702.
Article and author information
Author details
Funding
National Institute of Mental Health (R00MH111926)
- Christine M Constantinople
National Institute of Mental Health (R01MH125571)
- Cristina Savin
- Christine M Constantinople
Alfred P. Sloan Foundation
- Christine M Constantinople
Klingenstein-Simons Fellowship Award in Neuroscience
- Christine M Constantinople
National Science Foundation (1922658)
- Cristina Savin
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: This study was performed in accordance with the National Institutes of Health standards. Animal use procedures were approved by the Princeton University Institutional Animal Care and Use Committee (protocol #1853).
Reviewing Editor
- Emilio Salinas, Wake Forest School of Medicine, United States
Version history
- Received: May 14, 2021
- Accepted: October 20, 2021
- Accepted Manuscript published: October 25, 2021 (version 1)
- Version of Record published: November 25, 2021 (version 2)
Copyright
© 2021, Hocker et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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