title: Medial Orbitofrontal Neurons Preferentially Signal Cues Predicting Changes in Reward during Unblocking.
abstract: The orbitofrontal cortex (OFC) has been broadly implicated in the ability to use the current value of expected outcomes to guide behavior. Although value correlates have been prominently reported in lateral OFC, they are more often associated with more medial areas. Further, recent studies in primates have suggested a dissociation in which the lateral OFC is involved in credit assignment and representation of reward identity and more medial areas are critical to representing value. Previously, we used unblocking to test more specifically what information about outcomes is represented by OFC neurons in rats; consistent with the proposed dichotomy between the lateral and medial OFC, we found relatively little linear value coding in the lateral OFC (Lopatina et al., 2015). Here we have repeated this experiment, recording in the medial OFC, to test whether such value signals might be found there. Neurons were recorded in an unblocking task as rats learned about cues that signaled either more, less, or the same amount of reward. We found that medial OFC neurons acquired responses to these cues; however, these responses did not signal different reward values across cues. Surprisingly, we found that cells developed responses to cues predicting a change, particularly a decrease, in reward value. This is consistent with a special role for medial OFC in representing current value to support devaluation/revaluation sensitive changes in behavior.
  
  
  
  This study uniquely examines encoding in rodent mOFC at the single-unit level in response to cues that predict more, less, or no change in reward in rats during training in a Pavlovian unblocking task, finding more cells responding to change-predictive cues and stronger activity in response to cues predictive of less reward.
authors: National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland 21224, University of Maryland School of Medicine, Program in Neuroscience, Baltimore, Maryland 21201.
authors: Nina
authors: 0000-0001-6844-4941
authors: N
authors: Lopatina
authors: Department of Psychology, Boston College, Chestnut Hill, Massachusetts 02467.
authors: Michael A
authors: 0000-0001-8525-1260
authors: MA
authors: McDannald
authors: National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland 21224.
authors: Clay V
authors: CV
authors: Styer
authors: National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland 21224.
authors: Jacob F
authors: JF
authors: Peterson
authors: National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland 21224.
authors: Brian F
authors: BF
authors: Sadacca
authors: University of Maryland School of Medicine, Department of Anatomy and Neurobiology, Baltimore, Maryland 21201, and.
authors: Joseph F
authors: 0000-0001-5086-7559
authors: JF
authors: Cheer
authors: National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland 21224, University of Maryland School of Medicine, Department of Anatomy and Neurobiology, Baltimore, Maryland 21201, and Johns Hopkins University, Department of Neuroscience, Baltimore, Maryland 21205 geoffrey.schoenbaum@nih.gov.
authors: Geoffrey
authors: 0000-0001-8180-0701
authors: G
authors: Schoenbaum
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D003216:Conditioning, Operant / Q000502:physiology*; D003463:Cues; D008297:Male; D009474:Neurons / Q000502:physiology*; D009812:Odorants; D017397:Prefrontal Cortex / Q000166:cytology*; D051381:Rats; D020318:Rats, Long-Evans; D012201:Reward
keywords: Pavlovian; orbitofrontal; rat; single unit