Learning-related changes in response patterns of prefrontal neurons during instrumental conditioning.
A crucial aspect of organizing goal-directed behavior is the ability to form neural representations of relationships between environmental stimuli, actions and reinforcement. Very little is known yet about the neural encoding of response-reward relationships, a process which is deemed essential for purposeful behavior. To investigate this, tetrode recordings were made in the medial prefrontal cortex (PFC) of rats performing a Go-NoGo task. After task acquisition, a subset of neurons showed a sustained change in firing during the rewarded action sequence that was triggered by a specific visual cue. When these changes were monitored in the course of learning, they were seen to develop in parallel with the behavioral learning curve and were highly sensitive to a switch in reward contingencies. These sustained changes correlated with the reward-associated action sequence, not with sensory or reward-predicting properties of the cue or individual motor acts per se. This novel type of neural plasticity may contribute to the formation of response-reinforcer associations and of behavioral strategies for guiding goal-directed action.
Mulder
Antonius B
AB
Netherlands Institute for Brain Research, Meibergdreef 33, 1105 AZ, Amsterdam, The Netherlands. t.mulder@nih.knaw.nl
Nordquist
Rebecca E
RE
Orgüt
Okyay
O
Pennartz
Cyriel M A
CM
D000200:Action Potentials / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal; D003216:Conditioning, Operant / Q000502:physiology*; D004193:Discrimination Learning; D004594:Electrophysiology / Q000379:methods; D007858:Learning / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000502:physiology*; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000166:cytology* / Q000502:physiology*; D011597:Psychomotor Performance; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000502:physiology; D012054:Reinforcement, Psychology; D014796:Visual Perception