Expectancy-related changes in firing of dopamine neurons depend on orbitofrontal cortex.
The orbitofrontal cortex has been hypothesized to carry information regarding the value of expected rewards. Such information is essential for associative learning, which relies on comparisons between expected and obtained reward for generating instructive error signals. These error signals are thought to be conveyed by dopamine neurons. To test whether orbitofrontal cortex contributes to these error signals, we recorded from dopamine neurons in orbitofrontal-lesioned rats performing a reward learning task. Lesions caused marked changes in dopaminergic error signaling. However, the effect of lesions was not consistent with a simple loss of information regarding expected value. Instead, without orbitofrontal input, dopaminergic error signals failed to reflect internal information about the impending response that distinguished externally similar states leading to differently valued future rewards. These results are consistent with current conceptualizations of orbitofrontal cortex as supporting model-based behavior and suggest an unexpected role for this information in dopaminergic error signaling.
Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, USA. ytaka001@umaryland.edu
Yuji K
YK
Takahashi
Matthew R
MR
Roesch
Robert C
RC
Wilson
Kathy
K
Toreson
Patricio
P
O'Donnell
Yael
Y
Niv
Geoffrey
G
Schoenbaum
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D001710:Biotin / Q000031:analogs & derivatives / Q000378:metabolism; D002755:Choice Behavior; D003198:Computer Simulation; D004298:Dopamine / Q000378:metabolism*; D004558:Electric Stimulation; D008297:Male; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D017397:Prefrontal Cortex / Q000166:cytology*; D051381:Rats; D020318:Rats, Long-Evans; D012201:Reward; D013997:Time Factors; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D017557:Ventral Tegmental Area / Q000166:cytology / Q000502:physiology
C070614:neurobiotin; D001710:Biotin; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine