Calcium control of endocytic capacity at a CNS synapse
Calcium control of endocytic capacity at a CNS synapse
复制标题
DOI：
10.1523/jneurosci.1082-08.2008
复制
发表时间：
2008-06-25
影响因子：
5.3
通讯作者：
Ryan, Timothy A.
中科院分区：
文献类型：
--
作者：
Balaji, J.;Armbruster, Moritz;Ryan, Timothy A.
回收突触囊泡的能力是维持突触传递的神经末梢的重要特性。使用高灵敏度的光学方法在海马神经末梢分离的神经元在文化中，我们表明，调制的内吞作用可以通过扩大的内吞能力。我们的实验表明，内吞能力，突触囊泡的最大数量，可以在单个突触平行内化，是严格控制的细胞内钙水平。随着放电频率的增加而发生的细胞内钙水平的增加显著增加了内吞能力。在生理温度下，30 Hz放电后，这些突触能够内吞至少类似于28个平行的囊泡，每个囊泡的时间常数类似于6 s。这种对内吞能力的钙依赖性控制揭示了对高频活动的潜在有用的适应性反应，以在囊泡池耗尽的条件下增加内吞率。
The ability to recycle synaptic vesicles is a crucial property of nerve terminals that allows maintenance of synaptic transmission. Using high-sensitivity optical approaches at hippocampal nerve terminals in dissociated neurons in culture, we show that modulation of endocytosis can be achieved by expansion of the endocytic capacity. Our experiments indicate that the endocytic capacity, the maximum number of synaptic vesicles that can be internalized in parallel at individual synapses, is tightly controlled by intracellular calcium levels. Increasing levels of intracellular calcium, which occurs as firing frequency increases, significantly increases the endocytic capacity. At physiological temperature after 30 Hz firing, these synapses are capable of endocytosing at least similar to 28 vesicles in parallel, each with a time constant of similar to 6 s. This calcium-dependent control of endocytic capacity reveals a potentially useful adaptive response to high-frequency activity to increase endocytic rates under conditions of vesicle pool depletion.