Neurotransmitter release in chemical synapsesoccurs by fusion of the synaptic vesicle membrane andthe presynaptic membrane of the nerve terminal.Under normal conditions, initiation of this process byan action potential requires depolarization, Ca ionsinflux into the nerve terminal, and coordinated activity of many processes. However the role of membrane lipids in exocytosis has not been completelyunderstood. For example, membrane cholesterolhelps to control the fluidity and curvature of membranes, which is important for membrane ability tochange form and fuse. Cholesterol may determine themobility of integrated membrane proteins and evenchange their functions by integrating between the tailsof membrane sphingolipids [3, 6, 8]. Aggregation ofexocytosis proteins and Ca channels into the so-calledlipid rafts containing high concentrations of cholesterol may be an important mechanism regulating vesicle fusion [2, 4]. In this study, we tried to evaluate theeffect of membrane cholesterol on neurotransmitterrelease from motor nerve terminals. For this purpose,methyl-@[beta]-cyclodextrin (MCD), which efficiently removes cholesterol from membranes, wasused [5].
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