Format

Send to

Choose Destination
Neurobiol Aging. 2018 Jun;66:12-22. doi: 10.1016/j.neurobiolaging.2018.02.003. Epub 2018 Feb 10.

Levodopa improves response inhibition and enhances striatal activation in early-stage Parkinson's disease.

Author information

1
Department of Psychology, Integrative Neuroscience Program, Stony Brook University, Stony Brook, NY, USA. Electronic address: peter.manza@nih.gov.
2
Department of Neurology, Stony Brook University, Stony Brook, NY, USA.
3
Department of Psychology, Integrative Neuroscience Program, Stony Brook University, Stony Brook, NY, USA.
4
National Institute on Alcoholism and Alcohol Abuse, National Institutes of Health, Bethesda, MD, USA; National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA.
5
Department of Psychiatry, Yale University, New Haven, CT, USA; Department of Neuroscience, Yale University, New Haven, CT, USA; Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA; Beijing Huilongguan Hospital, Beijing, China.
6
Department of Psychology, Integrative Neuroscience Program, Stony Brook University, Stony Brook, NY, USA. Electronic address: hoi-chung.leung@stonybrook.edu.

Abstract

Dopaminergic medications improve the motor symptoms of Parkinson's disease (PD), but their effect on response inhibition, a critical executive function, remains unclear. Previous studies primarily enrolled patients in more advanced stages of PD, when dopaminergic medication loses efficacy, and patients were typically on multiple medications. Here, we recruited 21 patients in early-stage PD on levodopa monotherapy and 37 age-matched controls to perform the stop-signal task during functional magnetic resonance imaging. In contrast to previous studies reporting null effects in more advanced PD, levodopa significantly improved response inhibition performance in our sample. No significant group differences were found in brain activations to pure motor inhibition or error processing (stop success vs. error trials). However, relative to controls, the PD group showed weaker striatal activations to salient events (infrequent vs. frequent events: stop vs. go trials) and fronto-striatal task-residual functional connectivity; both were restored with levodopa. Thus, levodopa appears to improve an important executive function in early-stage PD via enhanced salient signal processing, shedding new light on the role of dopaminergic signaling in response inhibition.

KEYWORDS:

Basal ganglia; Cognitive control; Dopamine; Executive function; Movement disorders; Stop-signal task

PMID:
29501966
PMCID:
PMC6436810
[Available on 2019-06-01]
DOI:
10.1016/j.neurobiolaging.2018.02.003
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center