Department of Physiology, Tokyo Medical University.
Proc Jpn Acad Ser B Phys Biol Sci. 2017;93(10):802-820. doi: 10.2183/pjab.93.050.
For reliable transmission at chemical synapses, neurotransmitters must be released dynamically in response to neuronal activity in the form of action potentials. Stable synaptic transmission is dependent on the efficacy of transmitter release and the rate of resupplying synaptic vesicles to their release sites. Accurate regulation is conferred by proteins sensing Ca entering through voltage-gated Ca channels opened by an action potential. Presynaptic Ca concentration changes are dynamic functions in space and time, with wide fluctuations associated with different rates of neuronal activity. Thus, regulation of transmitter release includes reactions involving multiple Ca-dependent proteins, each operating over a specific time window. Classically, studies of presynaptic proteins function favored large invertebrate presynaptic terminals. I have established a useful mammalian synapse model based on sympathetic neurons in culture. This review summarizes the use of this model synapse to study the roles of presynaptic proteins in neuronal activity for the control of transmitter release efficacy and synaptic vesicle recycling.
为了在化学突触中实现可靠的传递，神经递质必须以动作电位的形式对神经元活动做出动态释放。稳定的突触传递依赖于递质释放的效率和突触小泡向释放部位重新供应的速度。通过动作电位打开的电压门控钙通道进入的钙感应蛋白赋予了准确的调节。突触前 Ca 浓度变化是时空上的动态函数，与不同的神经元活动速率相关联，存在广泛的波动。因此，递质释放的调节包括涉及多种 Ca 依赖性蛋白的反应，每个蛋白在特定的时间窗口内发挥作用。传统上，对突触前蛋白功能的研究倾向于使用大型无脊椎动物的突触前末梢。我已经建立了一种基于培养的交感神经元的有用的哺乳动物突触模型。本综述总结了使用该模型突触研究突触前蛋白在神经元活动控制递质释放效率和突触小泡再循环中的作用。
