α-Synuclein is expressed at high levels at presynaptic terminals, but defining its role in the regulation of neurotransmission under physiologically relevant conditions has proven elusive. We report that, in vivo, α-synuclein is responsible for the facilitation of dopamine release triggered by action potential bursts separated by short intervals (seconds) and a depression of release with longer intervals between bursts (minutes). These forms of presynaptic plasticity appear to be independent of the presence of β- and γ-synucleins or effects on presynaptic calcium and are consistent with a role for synucleins in the enhancement of synaptic vesicle fusion and turnover. These results indicate that the presynaptic effects of α-synuclein depend on specific patterns of neuronal activity.

α-突触核蛋白在突触前末端以高水平表达，但在生理相关条件下确定其在调节神经传递中的作用已被证明是难以捉摸的。我们报告说，在体内，α-突触核蛋白负责促进由以短间隔（秒）分隔的动作电位爆发触发的多巴胺释放和以较长间隔（分钟）间隔的释放抑制。这些形式的突触前可塑性似乎与β-和γ-突触核蛋白的存在或对突触前钙的影响无关，并且与突触核蛋白在增强突触小泡融合和周转中的作用一致。这些结果表明，α-突触核蛋白的突触前效应取决于神经元活动的特定模式。