Single-Vesicle\nElectrochemistry Reveals Polysaccharide\nfrom Glochidion eriocarpum Champ. Regulates\nVesicular Storage and Exocytotic Release of Dopamine

Polysaccharides, which are well-known natural macromolecules,\nhave\nbeen recognized for their protective effects on neurons and their\ninfluence on extracellular dopamine levels in the brain. It is crucial\nto investigate the impact of plant polysaccharides on neurotransmission,\nparticularly regarding the vesicular storage and exocytosis of neurotransmitters.\nIn this study, we demonstrated the possibility of studying how the\npolysaccharide from Glochidion eriocarpum Champ.(GPS) affects vesicle dopamine content and the dynamics of\nexocytosis in pheochromocytoma (PC12) cells using single-cell amperometry\n(SCA) and intracellular vesicle impact electrochemical cytometry (IVIEC).\nOur results unambiguously demonstrate that GPS effectively enhances\nvesicular neurotransmitter content and alters the dynamics of exocytosis,\nfavoring a smaller fraction of content released in exocytotic release,\nthereby inducing the partial release mode. These significant effects\nare attributed to GPS’s efficient elevation of calcium influx,\nsignificant alteration in the composition of exocytosis-related membrane\nlipids, and enhancement of free radical scavenging ability. These\nfindings not only establish GPS as a promising candidate for preventive\nor therapeutic interventions against neurodegenerative disorders but\nalso reiterate the importance of screening native neurologic drugs\nwith single-vesicle electrochemical approaches, the combination of\nSCA and IVIEC, from a neurotransmitter-centric perspective.