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Parkinson’s Disease
Volume 2015, Article ID 513452, 11 pages
http://dx.doi.org/10.1155/2015/513452
Research Article

Dopaminergic Modulation of Medial Prefrontal Cortex Deactivation in Parkinson Depression

1Department of Anatomy and Neurobiology, University of Kentucky, Lexington, KY 40536, USA
2Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, KY 40536, USA
3Department of Neurology, University of Kentucky, Lexington, KY 40536, USA
4Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA
5Veterans Administration Medical Center, Lexington, KY 40502, USA
6Department of Statistics, University of Kentucky, Lexington, KY 40536, USA
7Department of Biostatistics, University of Kentucky, Lexington, KY 40536, USA
8Department of Psychiatry, University of Kentucky, Lexington, KY 40536, USA
9Department of Behavioral Science, University of Kentucky, Lexington, KY 40536, USA

Received 28 July 2015; Accepted 25 November 2015

Academic Editor: Marjan Jahanshahi

Copyright © 2015 Anders H. Andersen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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.