Li Xiangning, Zhou Wei, Zeng Shaoqun, Liu Man, Luo Qingming
The Key Laboratory of Biomedical Photonics of Ministry of Education-Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China.
Biosens Bioelectron. 2007 Feb 15;22(7):1538-43. doi: 10.1016/j.bios.2006.05.030. Epub 2006 Jul 10.
Spontaneous neuronal activity plays an important role in development. However, the mechanism that underlies the long-term spontaneous developmental change of cultured neuronal networks in vitro is not well understood. To investigate the contribution of inhibitory and excitatory connections to the development of neuronal networks, dissociated neurons from an embryonic rat hippocampal formation were cultured on a multi-electrode array plate and spontaneous activities were recorded by multi-channel system. These spontaneous activities were compared to bicuculline-induced firings, which were recorded by 60 electrodes simultaneously from 1 to 14 weeks in vitro (WIV). The phenomena showed that the spontaneous firing activities changed from an initial pattern of synchronized bursts to a later pattern of high frequency random spikes. The bicuculline-induced firing activities transformed from a pattern of synchronized bursts throughout all active sites in 3 WIV, to a pattern of local synchronized or random spikes appearing in the intervals of synchronized bursts after 11 WIV, while the firing rate hardly changed. Kynurenic acid, a broad-spectrum glutamate receptor antagonist, blocked all activities while CNQX inhibited only the local synchronized or random spikes. These suggest that the inhibitory connection was age-dependent degraded in vitro and the developmental spontaneous firing pattern was built by the homeostatic balance of the excitatory-inhibitory connection networks. Long-term cultures on MEA provided a useful tool to measure the relationship between spontaneous developmental change and pharmacological influence in vitro.
自发神经元活动在发育过程中起着重要作用。然而，体外培养的神经元网络长期自发发育变化的潜在机制尚未得到充分理解。为了研究抑制性和兴奋性连接对神经元网络发育的贡献，将来自胚胎大鼠海马结构的解离神经元培养在多电极阵列板上，并通过多通道系统记录自发活动。将这些自发活动与荷包牡丹碱诱导的放电进行比较，荷包牡丹碱诱导的放电在体外1至14周（WIV）期间由60个电极同时记录。现象表明，自发放电活动从最初的同步爆发模式转变为后来的高频随机尖峰模式。荷包牡丹碱诱导的放电活动在3 WIV时从所有活跃部位的同步爆发模式转变为11 WIV后在同步爆发间隔中出现的局部同步或随机尖峰模式，而放电率几乎没有变化。犬尿喹啉酸，一种广谱谷氨酸受体拮抗剂，阻断了所有活动，而CNQX仅抑制局部同步或随机尖峰。这些表明抑制性连接在体外随年龄而降解，并且发育性自发放电模式是由兴奋性-抑制性连接网络的稳态平衡建立的。在MEA上的长期培养提供了一个有用的工具来测量体外自发发育变化与药理学影响之间的关系。
