Poster B128, Sunday, March 25, 8:00-10:00 am, Exhibit Hall C
Dopaminergic modulation of rostral-caudal fronto-striatal loops
David Amadeus Vogelsang1,2, Daniella J. Furman1,2, Mark D'Esposito1,2; 11. Helen Wills Neuroscience Institute, University of California, Berkeley, California, 94720, United States, 22. Department of Psychology, University of California, Berkeley, California, 94720, United States
Research has shown that the lateral prefrontal cortex (LPFC) may be hierarchically organized along a rostral-caudal functional gradient such that control processing becomes progressively more abstract from caudal to rostral frontal regions. A similar rostral-caudal gradient may also exist in the striatum. The neuromodulator dopamine plays an important role in fronto-striatal interactions and in cognitive control, however it remains unknown whether dopamine influences fronto-striatal connections in a way that accords with the known hierarchical processing gradient. Using a double-blind within-subject design, we analysed resting state fMRI data of healthy young subjects who were scanned twice at rest, once after administration of the dopamine D2 receptor agonist bromocriptine, and once after administration of a placebo. We determined whether dopamine stimulation modulated functional connectivity between frontal regions, that have previously been identified along the rostral-caudal gradient, and rostral and caudal striatal regions. We found that bromocriptine modulated LPFC-striatal connectivity between the inferior frontal sulcus and the mid and caudal part of the caudate. This finding is consistent with previous research demonstrating that the mid lateral frontal regions in humans have higher dopamine receptor density compared to more rostral and caudal frontal regions, suggesting that subregions within LPFC may be differentially modulated by brainstem dopaminergic projections. These results may provide new insights into the role dopamine may play in the hierarchy of cognitive control.
Topic Area: EXECUTIVE PROCESSES: Other