2 COMPONENTS OF TRANSMITTER RELEASE AT A CENTRAL SYNAPSE
2 COMPONENTS OF TRANSMITTER RELEASE AT A CENTRAL SYNAPSE
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DOI：
10.1073/pnas.91.26.12942
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发表时间：
1994-12-20
影响因子：
11.1
通讯作者：
STEVENS, CF
中科院分区：
文献类型：
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作者：
GODA, Y;STEVENS, CF
当突触前神经冲动到达海马神经元的兴奋性突触后，神经递质释放速度迅速增加，然后恢复到低水平，并伴有双相衰退。当Sr2+取代Ca2+离子时，这两种不同的动力学成分受到不同的影响。我们的研究结果与青蛙神经肌肉连接的经典研究相媲美，因此Ca2+激活的递质释放机制的基本方面似乎在中枢突触中保守。此外，我们使用的方法允许我们估计单个纽扣的平均神经递质释放率。Ca2+/Sr2+敏感性的差异观察与两个具有不同Ca2+亲和力的Calf传感器介导的释放机制一致：低亲和力Ca2+传感器促进快速同步释放阶段，而高亲和力传感器维持缓慢的异步释放阶段。
After the arrival of a presynaptic nerve impulse at an excitatory synapse in hippocampal neurons, the rate of neurotransmitter release increases rapidly and then returns to low levels with a biphasic decay. The two kinetically distinct components are differentially affected when Sr2+ is substituted for Ca2+ ions. Our findings are comparable to those of the classical studies for the frog neuromuscular junction, and thus the basic aspects of Ca2+-activated transmitter release machinery appear to be conserved in central synapses. The method we have used, in addition, permits us to estimate the average neurotransmitter release rate for a single bouton, The observation of differential Ca2+/Sr2+ sensitivity is consistent with a release mechanism mediated by two Calf sensors with distinct Ca2+ affinities: the low-affinity Ca2+ sensor facilitates the fast synchronous phase of release, whereas the high-affinity sensor sustains the slow asynchronous phase of release.