OSMOLALITY-INDUCED CHANGES IN EXTRACELLULAR VOLUME ALTER EPILEPTIFORM BURSTS INDEPENDENT OF CHEMICAL SYNAPSES IN THE RAT - IMPORTANCE OF NONSYNAPTIC MECHANISMS IN HIPPOCAMPAL EPILEPTOGENESIS
OSMOLALITY-INDUCED CHANGES IN EXTRACELLULAR VOLUME ALTER EPILEPTIFORM BURSTS INDEPENDENT OF CHEMICAL SYNAPSES IN THE RAT - IMPORTANCE OF NONSYNAPTIC MECHANISMS IN HIPPOCAMPAL EPILEPTOGENESIS
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DOI：
10.1016/0304-3940(90)90056-f
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发表时间：
1990-12-11
影响因子：
2.5
通讯作者：
TASKER, JG
中科院分区：
文献类型：
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作者：
DUDEK, FE;OBENAUS, A;TASKER, JG
非突触机制的贡献，大鼠海马CA1区锥体细胞的癫痫易感性进行了检查，在体外通过测试渗透压对同步神经元活动的影响，使用的解决方案，阻止化学突触传递前和突触后。 渗透压降低，细胞外容积缩小，引起或增强癫痫样爆发。膜不渗透溶质的渗透压增加，扩大细胞外容量，阻断或大大减少癫痫样放电。 因此，细胞外体积的减少可以通过非突触机制增强CA1海马神经元之间的同步化。 由于已知类似的渗透治疗可以改变几种癫痫模型中的癫痫样放电，因此在海马癫痫发生中，非突触机制可能比以前认识到的更重要，并且可能导致动物和人类大脑区域对癫痫发作的高敏感性。 这些数据还为在人体中观察到的血浆渗透压降低（可能与多种临床综合征相关）导致癫痫发作提供了可能的解释。
The contribution of non-synaptic mechanisms to the seizure susceptibility of rat CA1 hippocampal pyramidal cells was examined in vitro by testing the effects of osmolality on synchronous neuronal activity, using solutions which blocked chemical synaptic transmission both pre- and post-synaptically. Decreases in osmolality, which shrink the extracellular volume, caused or enhanced epileptiform bursting. Increases in osmolality with membrane-impermeant solutes, which expand the extracellular volume, blocked or greatly reduced epileptiform discharges. Reductions in the extracellular volume, therefore, can enhance synchronization among CA1 hippocampal neurons through non-synaptic mechanisms. Since similar osmotic treatments are known to modify epileptiform discharges in several models of epilepsy, non-synaptic mechanisms are probably more important in hippocampal epileptogenesis than previously realized and may contribute to the high susceptibility of this brain region to epileptic seizures in animals and humans. These data also provide a possible explanation for the observation in humans that decreased plasma osmolality, which can be associated with a wide range of clinical syndromes, leads to seizures.