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美国卫生研究院文献>The Journal of Neuroscience
>The mechanisms of generation and propagation of synchronized bursting in developing networks of cortical neurons
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The mechanisms of generation and propagation of synchronized bursting in developing networks of cortical neurons
The characteristics and mechanisms of synchronized firing in developing networks of cultured cortical neurons were studied using multisite recording through planar electrode arrays (PEAs). With maturation of the network (from 3 to 40 d after plating), the frequency and propagation velocity of bursts increased markedly (approximately from 0.01 to 0.5 Hz and from 5 to 100 mm/sec, respectively), and the sensitivity to extracellular magnesium concentration (0–10 mM) decreased. The source of spontaneous bursts, estimated from the relative delay of onset of activity between electrodes, varied randomly with each burst. Physical separation of synchronously bursting networks into several parts using an ultraviolet laser, divided synchronous bursting into different frequencies and phases in each part. Focal stimulation through the PEA was effective at multiple sites in eliciting bursts, which propagated over the network from the site of stimulation. Stimulated bursts exhibited both an absolute refractory period and a relative refractory period, in which partially propagating bursts could be elicited. Periodic electrical stimulation (at 1 to 30 sec intervals) produced slower propagation velocities and smaller numbers of spikes per burst at shorter stimulation intervals. These results suggest that the generation and propagation of spontaneous synchronous bursts in cultured cortical neurons is governed by the level of spontaneous presynaptic firing, by the degree of connectivity of the network, and by a distributed balance between excitation and recovery processes.
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机译:利用通过平面电极阵列(PEA)的多位记录,研究了在培养的皮质神经元发育网络中同步放电的特征和机制。随着网络的成熟(电镀后3到40 d),猝发的频率和传播速度显着增加(分别从0.01到0.5 Hz和从5到100 mm / sec),以及对细胞外镁浓度的敏感性(0–10 mM)减少。根据电极之间活动开始的相对延迟估计的自发爆发源,随每个爆发而随机变化。使用紫外激光将同步爆发网络物理分为几个部分,并将每个部分的同步爆发分为不同的频率和相位。通过PEA进行的局部刺激在多个部位均有效,可引起爆发,这些爆发从刺激部位通过网络传播。受激爆发具有绝对不应期和相对不应期,其中可以引起部分传播的爆发。周期性的电刺激(以1到30秒为间隔)会产生较慢的传播速度,并且在较短的刺激间隔下每次爆发会产生较少的尖峰。这些结果表明,在培养的皮层神经元中自发同步爆发的产生和传播受自发突触前放电水平,网络的连通程度以及激发和恢复过程之间的分布平衡的控制。
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