Exocytosis determination of SH-SY5Y single cell stimulated by different stimulants on indium tin oxide (ITO) micro-pore electrode

The human neuroblastoma SH-SY5Y cell line has been used as a model to study mechanisms of neurotransmitter release. In order to study the mechanism of SH-SY5Y single cell exocytosis stimulated by different stimulants, including high K⁺, 3-(1-nitroso-2-pyrrolidinyl) pyridine and nicotine, a type of indium tin oxide (ITO) micro-pore electrode was used to obtain the corresponding amperometric response time. When the cell is stimulated by 0.1 M K⁺, almost immediate exocytosis could be detected, due to the rapid depolarization of cell membrane. However, the stimulations with 1 mM nicotine and 3-(1-nitroso-2-pyrrolidinyl) pyridine result in a short delay between stimulation and exocytosis, which can be correlated with the time needed for binding of the stimulant to the nicotinic acetylcholine (ACh) receptor and the induction of post-binding phenomena. Thus, the response time of SH-SY5Y single cell exocytosis is significantly affected by the exocytosis mechanisms.