Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University, School of Medicine, Springfield, IL 62794-9626, USA.
J Neural Eng. 2010 Feb;7(1):16008. doi: 10.1088/1741-2560/7/1/016008. Epub 2010 Jan 19.
Neurons cultured on multielectrode arrays almost always lack external stimulation except during the acute experimental phase. We have investigated the effects of chronic stimulation during the course of development in cultured hippocampal neural networks by applying paired pulses at half of the electrodes for 0, 1 or 3 r/day for 8 days. Spike latencies increased from 4 to 16 ms as the distance from the stimulus increased from 200 to 1700 microm, suggesting an average of four synapses over this distance. Compared to no chronic stimulation, our results indicate that chronic stimulation increased evoked spike counts per stimulus by 50% at recording sites near the stimulating electrode and increased the instantaneous firing rate. On trials where both pulses elicited responses, spike count was 40-80% higher than when only one of the pulses elicited a response. In attempts to identify spike amplitude plasticity, we found mainly amplitude variation with different latencies suggesting recordings from neurons with different identities. These data suggest plastic network changes induced by chronic stimulation that enhance the reliability of information transmission and the efficiency of multisynaptic network communication.
在多电极阵列上培养的神经元几乎总是缺乏外部刺激，除非在急性实验阶段。我们通过在一半的电极上施加成对脉冲，在培养的海马神经网络的发育过程中进行慢性刺激，研究了慢性刺激的影响，刺激频率为 0、1 或 3 次/天，持续 8 天。随着距离刺激源的距离从 200 微米增加到 1700 微米，尖峰潜伏期从 4 毫秒增加到 16 毫秒，表明在此距离上平均有四个突触。与没有慢性刺激相比，我们的结果表明，在靠近刺激电极的记录部位，慢性刺激使每个刺激的诱发尖峰计数增加了 50%，并提高了瞬时放电率。在两个脉冲都能引起反应的试验中，尖峰计数比只有一个脉冲能引起反应时高出 40-80%。在试图识别尖峰幅度可塑性时，我们发现主要是潜伏期不同的幅度变化，这表明记录的是具有不同身份的神经元。这些数据表明，慢性刺激诱导的网络变化增强了信息传递的可靠性和多突触网络通信的效率。
