RNA interference of endophilin A2 inhibits synaptic vesicle endocytosis in rat hippocampal neurons

AIM: To investigate the effect of endophilin A2 on synaptic vesicle endocytosis in rat hippocampal neurons.METHODS: The siRNAs for endophilin A2 isoform were designed, and the efficacy and specificity of these siRNAs were determined by Western blot. Immunostaining was performed to verify the interference efficiency of the siRNA for endogenous endophilin A2 in the hippocampal neurons. Excitatory postsynaptic currents (EPSCs) were recorded on cultured hippocampal neurons using dual whole-cell recordings by evoking the transfected presynaptic neurons in various stimulation patterns. RESULTS: The result of immunostaining in cultured hippocampal neurons demonstrated that the siRNA of endophilin A2 inhibited the expression of endogenous endophilin A2 significantly (P<0.05). The results of dual whole-cell recordings showed that no significant difference in the EPSCs amplitude evoked between endophilin A2 knockdown neurons and control was observed when stimulated at low frequency (0.1 Hz). The amplitude of normalized EPSCs evoked in endophilin A2 knockdown neurons decreased significantly for both single-train and multiple-train stimulations (P<0.05).CONCLUSION: An effective siRNA of endophilin A2 was screened out successfully. Knockdown of endophilin A2 isoform does not affect synaptic vesicle exocytosis, but inhibits synaptic vesicle endocytosis in rat hippocampal neurons.