Neurovascular coupling alteration in drug-naïve Parkinson's disease: The underlying molecular mechanisms and levodopa's restoration effects

•PD patients exhibited neurovascular coupling (NVC) alteration in the striato-thalamo-cortical motor circuit and motor control regions.•The NVC dysfunction could be driven by dopaminergic and nondopaminergic systems (serotoninergic, opioid, and cholinergic).•Levodopa ameliorated abnormal NVC in most of these regions, where there were primarily neuronal activity changes with limited blood perfusion modifications.