title: Dopaminergic Modulation of Medial Prefrontal Cortex Deactivation in Parkinson Depression.
abstract: Parkinson's disease (PD) is associated with emotional abnormalities. Dopaminergic medications ameliorate Parkinsonian motor symptoms, but less is known regarding the impact of dopaminergic agents on affective processing, particularly in depressed PD (dPD) patients. The aim of this study was to examine the effects of dopaminergic pharmacotherapy on brain activation to emotional stimuli in depressed versus nondepressed Parkinson disease (ndPD) patients. Participants included 18 ndPD patients (11 men, 7 women) and 10 dPD patients (7 men, 3 women). Patients viewed photographs of emotional faces during functional MRI. Scans were performed while the patient was taking anti-Parkinson medication and the day after medication had been temporarily discontinued. Results indicate that dopaminergic medications have opposite effects in the prefrontal cortex depending upon depression status. DPD patients show greater deactivation in the ventromedial prefrontal cortex (VMPFC) on dopaminergic medications than off, while ndPD patients show greater deactivation in this region off drugs. The VMPFC is in the default-mode network (DMN). DMN activity is negatively correlated with activity in brain systems used for external visual attention. Thus dopaminergic medications may promote increased attention to external visual stimuli among dPD patients but impede normal suppression of DMN activity during external stimulation among ndPD patients.
authors.affiliation: Department of Anatomy and Neurobiology, University of Kentucky, Lexington, KY 40536, USA; Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Anders H
authors.initials: AH
authors.lastname: Andersen
authors.affiliation: Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, KY 40536, USA; Department of Neurology, University of Kentucky, Lexington, KY 40536, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Charles D
authors.initials: CD
authors.lastname: Smith
authors.affiliation: Department of Neurology, University of Kentucky, Lexington, KY 40536, USA; Veterans Administration Medical Center, Lexington, KY 40502, USA.
authors.forename: John T
authors.initials: JT
authors.lastname: Slevin
authors.affiliation: Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA; Department of Statistics, University of Kentucky, Lexington, KY 40536, USA; Department of Biostatistics, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Kryscio
authors.affiliation: Department of Psychiatry, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Martin
authors.affiliation: Department of Neurology, University of Kentucky, Lexington, KY 40536, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA; Department of Psychiatry, University of Kentucky, Lexington, KY 40536, USA; Department of Behavioral Science, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Schmitt
authors.affiliation: Department of Neurology, University of Kentucky, Lexington, KY 40536, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA; Department of Behavioral Science, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Lee X
authors.initials: LX
authors.lastname: Blonder