Title
Value encoding in the globus pallidus: fMRI reveals an interaction effect between reward and dopamine drive.
Abstract
The external part of the globus pallidus (GPe) is a core nucleus of the basal ganglia (BG) whose activity is disrupted under conditions of low dopamine release, as in Parkinson's disease. Current models assume decreased dopamine release in the dorsal striatum results in deactivation of dorsal GPe, which in turn affects motor expression via a regulatory effect on other nuclei of the BG. However, recent studies in healthy and pathological animal models have reported neural dynamics that do not match with this view of the GPe as a relay in the BG circuit. Thus, the computational role of the GPe in the BG is still to be determined. We previously proposed a neural model that revisits the functions of the nuclei of the BG, and this model predicts that GPe encodes values which are amplified under a condition of low striatal dopaminergic drive. To test this prediction, we used an fMRI paradigm involving a within-subject placebo-controlled design, using the dopamine antagonist risperidone, wherein healthy volunteers performed a motor selection and maintenance task under low and high reward conditions. ROI-based fMRI analysis revealed an interaction between reward and dopamine drive manipulations, with increased BOLD activity in GPe in a high compared to low reward condition, and under risperidone compared to placebo. These results confirm the core prediction of our computational model, and provide a new perspective on neural dynamics in the BG and their effects on motor selection and cognitive disorders.
Year
DOI
Venue
2018
10.1016/j.neuroimage.2018.02.048
NeuroImage
Keywords
Field
DocType
Globus pallidus,Indirect pathway,Basal ganglia,Dopamine,Parkinson's disease
Neuroscience,Globus pallidus,Dopamine antagonist,Striatum,Psychology,Cognitive psychology,Dopaminergic,Dopamine,Cognition,Risperidone,Basal ganglia
Journal
Volume
ISSN
Citations 
173
1053-8119
1
PageRank 
References 
Authors
0.38
7
6
Name
Order
Citations
PageRank
Vincenzo G. Fiore120.76
Tobias Nolte210.38
Francesco Rigoli3394.36
Peter Smittenaar430.79
Xiaosi Gu5273.73
Raymond J Dolan641949.74