Extracellular calcium fluctuations and intracellular potentials in the cortex during the slow sleep oscillation
Extracellular calcium fluctuations and intracellular potentials in the cortex during the slow sleep oscillation
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DOI：
10.1152/jn.2001.85.3.1346
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发表时间：
2001-03-01
影响因子：
2.5
通讯作者：
Amzica, F
中科院分区：
文献类型：
--
作者：
Massimini, M;Amzica, F
在慢波睡眠中，皮层神经元的主要活动包括膜电位在去极化值和超极化值之间的同步和节律性变化。后者是长时间(200-600毫秒)的静默期。导致这种皮质网络活动周期性中断的机制尚不清楚。在这里，我们报告了一个类似于20%的细胞外钙离子浓度([Ca](OUT))的下降，在慢速睡眠振荡的去极化阶段的开始和偏移之间，在皮质中逐渐发生。由于[Ca](Out)对突触传递具有高增益调制作用，我们估计了相关的递质释放概率，发现相应的下降了50%。因此，在慢波睡眠期间，皮层网络中出现的静默期被反复的[Ca](Out)耗竭所促进。
During slow wave sleep the main activity of cortical neurons consists of synchronous and rhythmic alternations of the membrane potential between depolarized and hyperpolarized values. The latter are long-lasting (200-600 ms) periods of silence. The mechanisms responsible for this periodical interruption of cortical network activity are unknown. Here we report a decrease of similar to 20% in the extracellular calcium concentration ([Ca](out)) progressively taking place in the cortex between the onset and the offset of the depolarizing phase of the slow sleep oscillation. Since [Ca](out) exerts a high gain modulation of synaptic transmission, we estimated the associated transmitter release probability and found a corresponding 50% drop. Thus the periods of silence occurring in the cortical network during slow wave sleep are promoted by recurrent [Ca](out) depletions.