Optical monitoring of progressive synchronization in dentate granule cells during population burst activities
Optical monitoring of progressive synchronization in dentate granule cells during population burst activities
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DOI：
10.1111/j.1460-9568.2005.04167.x
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发表时间：
2005-06-01
影响因子：
3.4
通讯作者：
Inoue, M
中科院分区：
文献类型：
--
作者：
Murayama, M;Miyazaki, K;Inoue, M
监测多个神经元对于理解神经元网络的活动至关重要。虽然细胞群的钙成像是研究神经结构网络动力学的有效方法，但由于细胞重叠，很难从密集排列的结构（如齿状回的颗粒细胞层）中成像。我们开发了一种新的方法，用俄勒冈绿488 BAPTA-1 (OGB-1) AM在大鼠海马切片中标记多颗粒细胞与Ca2+指示剂。用放置在齿状回颗粒细胞层的玻璃电极监测50 μ m 4-氨基吡啶诱导的同步爆发活动（0.3-1.4 Hz）。在爆发活动期间，用单细胞分辨率的冷却CCD相机监测多个（4-12）颗粒细胞自发发生的动作电位诱导的Ca2+瞬态。多神经元放电模式的时间结构是通过Ca2+瞬态来确定的。在细胞外电极记录的每一个单脉冲事件中，每个神经元在200毫秒的时间窗内同步放电。随着时间的推移（< 7.5 min），从单次突发事件的开始时间到其中一次Ca2+瞬态的潜伏期及其方差减小。这些结果表明，单次突发事件中动作电位的同步性随着突发活动的进行而增强。这种渐进式同步可能是制造自组织神经元网络的关键特征。
Monitoring multiple neurons is essential for understanding neuronal network activities. While calcium imaging from a population of cells is an effective method to study the network dynamics of a neural structure, it has been difficult to image from densely packed structures, such as the granule cell layer of the dentate gyrus, due to overlap of the cells. We have developed a novel method to label multiple granule cells with a Ca2+ indicator in rat hippocampal slices using Oregon Green 488 BAPTA-1 (OGB-1) AM. Synchronized burst activities (0.3-1.4 Hz), which were induced by applying 50 mu m 4-aminopyridine, were monitored extracellularly with a glass electrode placed at the granule cell layer in the dentate gyrus. During the burst activities, spontaneously occurring action potential-induced Ca2+ transients from multiple (4-12) granule cells were monitored with a cooled CCD camera with single-cell resolution. Temporal structures of firing patterns from the multiple neurons were determined from Ca2+ transients. In each single-burst-event recorded from the extracellular electrode, each neuron fired synchronously within a 200 ms time window. The latency and its variance from the onset time of the single-burst-events to one of the Ca2+ transients decreased over time (< 7.5 min). These results indicate that the synchrony of the action potentials within a single-burst-event was enhanced as the burst activities proceeded. This progressive synchronization may be a key feature in making self-organizing neuronal networks.