Joseph Mandeville1, Christin Sander2, Bruce Jenkins3, Bruce Rosen3, Jacob Hooker3, Ciprian Catana3, Wim Vanduffel3, Nathaniel Alpert3, Marc Normandin
1Radiology, Massachusetts General Hospital, Boston, MA, United States; 2Massachusetts Institute of Technology, United States; 3Radiology, Massachusetts General Hospital, United States
fMRI data in an awake monkey during amphetamine challenge were acquired simultaneously with PET measurement of D2 receptor density. A compartment model of the fMRI response, based upon the competing effects of stimulation at D1 and D2 receptors, was developed to describe the temporal shape and magnitude of the fMRI response, while also accurately describing other reported fMRI responses in monkeys and rats at different levels of drug-induced dopamine. The model-inferred D2 contribution to fMRI signal correlated linearly with measured D2 receptor density. Simultaneous PET/MR measurements of dynamic dopaminergic function will be required to further refine the model.