Cortical Single-Cell Primers of Abnormal Brain Activity in Parkinson's Disease

Abnormal brain oscillatory activity is a well-established hallmark of bradykinesia and motor impairment in Parkinson's disease (PD), yet its molecular underpinnings remain unclear. To address this gap, we analyzed over 100,000 single-cell RNA transcriptomes from fresh dorsolateral prefrontal cortex tissue of individuals with PD and non-PD controls, undergoing deep brain stimulation-2 cohorts, which open up an unprecedent window to the characterization of human cortical brain tissue, aiming to uncover the molecular mechanisms of abnormal brain oscillatory activity in PD. Fresh brain tissue samples offer a unique opportunity to precisely elucidate the molecular underpinnings of known, clinically relevant electrophysiological hallmarks of neurodegeneration, which can be used to inform targeted therapeutic strategies. We depicted in microglia and astrocytes enrichment of mitochondrial electron transport and oxidative phosphorylation pathways, which were directly linked to the increase of pathological brain activity and the decrease of prokinetic brain activity. Additionally, the abnormal phase-amplitude coupling of beta-gamma brain activity was related to the dysfunction of oligodendrocyte precursor cells and inflammasome activation mediated by lymphocyte-driven adaptive immunity. We identified a distinct set of dysregulated genes from the mitogen-activated protein kinase phosphorylation pathways, mitochondrial electron transport at the intersection of neuroinflammation and neurodegeneration, suggesting pivotal roles in PD pathology. This unique dataset provides unprecedented insights into the immune and metabolic dysregulation underlying PD, offering a mechanistic framework for understanding invasive transcriptomic biomarkers related to prokinetic and pathologic brain activity in PD.