New studies in Parkinson’s disease (PD) are expanding understanding of disease mechanisms and therapeutic approaches. Research highlights glymphatic system asymmetry correlating with symptom onset side and demonstrates theta-frequency deep brain stimulation improving conflict resolution in PD patients. Additional work elucidates distinct nigral and cortical molecular pathways and explores the safety of fecal microbiota transplantation as a novel intervention. Collectively, these findings refine the neurobiology and potential treatments of PD.