Action-outcome relationships are represented differently by medial prefrontal and orbitofrontal cortex neurons during action execution

J Neurophysiol. 2015 Dec;114(6):3374-85. doi: 10.1152/jn.00884.2015. Epub 2015 Oct 14.


Internal representations of action-outcome relationships are necessary for flexible adaptation of motivated behavior in dynamic environments. Prefrontal cortex (PFC) is implicated in flexible planning and execution of goal-directed actions, but little is known about how information about action-outcome relationships is represented across functionally distinct regions of PFC. Here, we observe distinct patterns of action-evoked single unit activity in the medial prefrontal cortex (mPFC) and orbitofrontal cortex (OFC) during a task in which the relationship between outcomes and actions was independently manipulated. The mPFC encoded changes in the number of actions required to earn a reward, but not fluctuations in outcome magnitude. In contrast, OFC neurons decreased firing rates as outcome magnitude was increased, but were insensitive to changes in action requirement. A subset of OFC neurons also tracked outcome availability. Pre-outcome anticipatory activity in both mPFC and OFC was altered when reward expectation was reduced, but did not differ with outcome magnitude. These data provide novel evidence that PFC regions encode distinct information about the relationship between actions and impending outcomes during action execution.

Keywords: electrophysiology; instrumental behavior; orbitofrontal cortex; prefrontal cortex; reward.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Action Potentials*
  • Animals
  • Anticipation, Psychological
  • Male
  • Neurons / physiology*
  • Prefrontal Cortex / cytology
  • Prefrontal Cortex / physiology*
  • Rats
  • Rats, Sprague-Dawley
  • Reward*