Coherent theta activity in the medial and orbital frontal cortices encodes reward value
Abstract
This study examined how the medial frontal (MFC) and orbital frontal (OFC) cortices process reward information. We simultaneously recorded local field potentials in the two areas as rats consumed liquid sucrose rewards. Both areas exhibited a 4-8 Hz 'theta' rhythm that was phase locked to the lick cycle. The rhythm tracked shifts in sucrose concentrations and fluid volumes, demonstrating that it is sensitive to differences in reward magnitude. The coupling between the rhythm and licking was stronger in MFC than OFC and varied with response vigor and absolute reward value in the MFC. Spectral analysis revealed zero-lag coherence between the cortical areas, and found evidence for a directionality of the rhythm, with MFC leading OFC. Our findings suggest that consummatory behavior generates simultaneous theta range activity in the MFC and OFC that encodes the value of consumed fluids, with the MFC having a top-down role in the control of consumption.
Data availability
Code, raw data, and summaries of grouped data are available on the Open Science Framework.
Article and author information
Author details
Funding
National Institute on Drug Abuse (DA046375)
- Mark Laubach
National Science Foundation (GRP)
- Linda M Amarante
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Erin L Rich, Icahn School of Medicine at Mount Sinai, United States
Ethics
Animal experimentation: All procedures carried out in this set of experiments were approved by the Animal Care and Use Committee at American University (Washington, DC). The approved protocol number is 1710. All procedures conformed to the standards of the National Institutes of Health Guide for the Care and Use of Laboratory Animals. All efforts were taken to minimize the number of animals used and to reduce pain and suffering.
Version history
- Received: September 23, 2020
- Accepted: September 9, 2021
- Accepted Manuscript published: September 10, 2021 (version 1)
- Version of Record published: September 22, 2021 (version 2)
- Version of Record updated: September 24, 2021 (version 3)
Copyright
© 2021, Amarante & Laubach
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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