Network bursts in hippocampal microcultures are terminated by exhaustion of vesicle pools
Network bursts in hippocampal microcultures are terminated by exhaustion of vesicle pools
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DOI：
10.1152/jn.00969.2010
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发表时间：
2011-11-01
影响因子：
2.5
通讯作者：
Segal, Menahem
中科院分区：
文献类型：
--
作者：
Cohen, Dror;Segal, Menahem
放大图片作者：John D.海马微培养物中的网络爆发通过耗尽囊泡池而终止。J Neurophysiol 106：2314-2321，2011.首次发表于2011年8月10日; doi：10.1152/jn.00969.2010.-同步的网络活动是大脑的一个基本属性。然而，决定网络突发持续时间的蜂窝机制还没有完全理解。在本研究中，通过触发由4-30个海马神经元组成的静止微培养物中单个神经元的动作电位来诱发同步网络爆发。诱发的爆发持续时间，类似于2秒，取决于前一次爆发后的恢复时间。虽然35秒的爆发间隔使全长爆发，他们缩短了一半，在5秒的时间间隔。这种短脉冲持续时间的减少不能归因于突触后参数，如谷氨酸受体脱敏，积累后超极化，抑制性音调，或钠通道失活。降低细胞外Ca（2+）浓度（[Ca（2+）]（o））缓解了短间隔对爆发持续时间的影响，而用α-latrotoxin耗尽突触囊泡逐渐消除了网络爆发。最后，短暂暴露于高[K（+）]（o）减慢了突发放电后的恢复时间。我们的结论是，限制因素调节爆发持续时间是最有可能的突触前资源的耗尽。
Cohen D, Segal M. Network bursts in hippocampal microcultures are terminated by exhaustion of vesicle pools. J Neurophysiol 106: 2314-2321, 2011. First published August 10, 2011; doi:10.1152/jn.00969.2010.-Synchronized network activity is an essential attribute of the brain. Yet the cellular mechanisms that determine the duration of network bursts are not fully understood. In the present study, synchronized network bursts were evoked by triggering an action potential in a single neuron in otherwise silent microcultures consisting of 4-30 hippocampal neurons. The evoked burst duration, similar to 2 s, depended on the recovery time after a previous burst. While interburst intervals of 35 s enabled full-length bursts, they were shortened by half at 5-s intervals. This reduction in burst duration could not be attributed to postsynaptic parameters such as glutamate receptor desensitization, accumulating afterhyperpolarization, inhibitory tone, or sodium channel inactivation. Reducing extracellular Ca(2+) concentration ([Ca(2+)](o)) relieved the effect of short intervals on burst duration, while depletion of synaptic vesicles with alpha-latrotoxin gradually eliminated network bursts. Finally, a transient exposure to high [K(+)](o) slowed down the recovery time following a burst discharge. We conclude that the limiting factor regulating burst duration is most likely the depletion of presynaptic resources.