Cellular basis of neuronal synchrony in epilepsy.
Cellular basis of neuronal synchrony in epilepsy.
复制标题
DOI：
--
复制
发表时间：
1986
影响因子：
--
通讯作者：
R. Wong;R. Traub;R. Miles
中科院分区：
文献类型：
--
作者：
R. Wong;R. Traub;R. Miles
在实验性癫痫研究中，皮层神经元群体的同步放电经常被观察到是发作间期棘波和强直性发作的基础。最近的研究表明，在用青霉素、印防己毒素或荷包牡丹碱等惊厥药处理的大脑皮层切片中，也会出现类似的同步放电。由体外制备提供的有利的实验条件，促进了详细的检查细胞的基础上产生的癫痫神经元同步。在这一章中，我们将回顾一些实验观察的神经元同步化，并描述其产生的机制的基础上的计算机模拟方法。癫痫同步化的体外观察需要三个因素。首先，皮质神经元可能固有地产生动作电位的爆发。第二，存在反复出现的兴奋性连接，这些连接足够强大，以至于爆发活动可以在突触连接的神经元之间传播。第三，局部神经元回路内的抑制必须被充分减弱，以允许兴奋通过反复出现的兴奋性连接传播。计算机模拟研究已经基于这些假设，使用神经元网络，其中每个细胞连接到一个以上的突触后神经元。在一个细胞中启动的爆发激发了所有的跟随细胞，并且越来越多的细胞的顺序募集最终导致群体的同时放电。最近的一些实验观察为神经元同步的建议方案提供了证据。同时成对的细胞内记录提供了直接的证据，表明突触前细胞中的动作电位爆发可以激活突触后的动作电位。此外，它表明，在一个神经元群体中的自发放电的节奏可以影响的人口内的一个神经元的活动。
Synchronized discharge of populations of cortical neurons are often observed to underly both the interictal spikes and tonic seizures generated in experimental epilepsy studies. Recently it has been shown that similar synchronized discharges occur in cortical brain slices treated with convulsants such as penicillin, picrotoxin, or bicuculline. The favorable experimental conditions offered by the in vitro preparation have facilitated a detailed examination on the cellular basis for the generation of the epileptic neuronal synchrony. In this chapter we shall review some experimental observations on the neuronal synchronization and describe a mechanism for its generation based on the computer simulation approach. Three factors are considered to be essential for epileptic synchronization observation in vitro. First, cortical neurons may intrinsically generate bursts of action potentials. Second, recurrent excitatory connections exist that are sufficiently powerful that bursting activity may spread between synaptically connected neurons. Third, inhibition within the local neuronal circuit must be adequately attenuated to allow excitation to spread through the recurrent excitatory connections. Computer simulation studies have been based on these assumptions, using neuronal networks where each cell is connected to more than one postsynaptic neuron. Bursting initiated in one cell excites all its follower cells, and the sequential recruitment of an increasing number of cells eventually leads to a simultaneous discharge of the population. A number of recent experimental observations lend credence to the proposed scheme for neuronal synchrony. Simultaneous paired intracellular recordings provided direct evidence that a burst of action potentials in a presynaptic cell can activate action potentials postsynaptically. Furthermore, it is shown that the rhythm of spontaneous discharge in a neuronal population can be influenced by the activity of one neuron within the population.