Intracellular features predicted by extracellular recordings in the hippocampus in vivo
Intracellular features predicted by extracellular recordings in the hippocampus in vivo
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DOI：
10.1152/jn.2000.84.1.390
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发表时间：
2000-07-01
影响因子：
2.5
通讯作者：
Buzsáki, G
中科院分区：
文献类型：
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作者：
Henze, DA;Borhegyi, Z;Buzsáki, G
对清醒行为动物进行多通道四极阵列记录提供了一种记录大量神经元活动的强大方法。如果可以从细胞外记录的信号中提取有关神经元细胞内状态的更多信息，则可以扩展该方法的功能。为此，我们同时记录了麻醉大鼠海马 CA1 锥体细胞和中间神经元的细胞内和细胞外信号。我们发现可以从细胞外尖峰波形推断出一些细胞内参数。细胞内动作电位的宽度由细胞外尖峰上的不同点精确定义。细胞内动作电位的幅度变化通过细胞外尖峰的初始负相的幅度变化来反映，并且这些幅度变化取决于网络的状态。此外，来自树突的细胞内记录与来自体细胞的同时细胞外记录表明，平均而言，动作电位在体周区域启动并以 1.68 m/s 的速度传播到树突。最后我们确定海马 CA1 区的四极管理论上应该能够记录来自大约 1000 个神经元的电信号。其中，60-100 个神经元应产生足够幅度的尖峰，以便可以从噪声中检测到，并允许使用当前的空间聚类方法将它们分开。该理论最大值与每个四极通常检测到的大约六个单元形成对比。由此，我们得出结论，在任何给定的行为条件下，很大一部分海马 CA1 锥体细胞是沉默的。
Multichannel tetrode array recording in awake behaving animals provides a powerful method to record the activity of large numbers of neurons. The power of this method could be extended if further information concerning the intracellular state of the neurons could be extracted from the extracellularly recorded signals. Toward this end, we have simultaneously recorded intracellular and extracellular signals from hippocampal CA1 pyramidal cells and interneurons in the anesthetized rat. We found that several intracellular parameters can be deduced from extracellular spike waveforms. The width of the intracellular action potential is defined precisely by distinct points on the extracellular spike. Amplitude changes of the intracellular action potential are reflected by changes in the amplitude of the initial negative phase of the extracellular spike, and these amplitude changes are dependent on the state of the network. In addition, intracellular recordings from dendrites with simultaneous extracellular recordings from the soma indicate that, on average, action potentials are initiated in the perisomatic region and propagate to the dendrites at 1.68 m/s. Finally we determined that a tetrode in hippocampal area CA1 theoretically should be able to record electrical signals from similar to 1,000 neurons. Of these, 60-100 neurons should generate spikes of sufficient amplitude to be detectable from the noise and to allow for their separation using current spatial clustering methods. This theoretical maximum is in contrast to the approximately six units that are usually detected per tetrode. From this, we conclude that a large percentage of hippocampal CA1 pyramidal cells are silent in any given behavioral condition.