REGIONAL VARIATION OF EXTRACELLULAR-SPACE IN THE HIPPOCAMPUS
REGIONAL VARIATION OF EXTRACELLULAR-SPACE IN THE HIPPOCAMPUS
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DOI：
10.1126/science.2382142
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发表时间：
1990-08-10
期刊：
影响因子：
56.9
通讯作者：
DINGLEDINE, R
中科院分区：
文献类型：
--
作者：
MCBAIN, CJ;TRAYNELIS, SF;DINGLEDINE, R
海马对癫痫发作和缺血性细胞损伤的异常易感性的原因还不清楚。海马的CA1锥体子区特别容易受到缺血后癫痫发作活动和损伤的影响。研究了细胞外体积存在区域差异的可能性，这可能会影响海马神经元的兴奋性和对损伤的反应。CA1层的脑皮层表现出异常低的细胞外容积分数（EVF）为0.12，而CA3和齿状核的EVF相当高，分别为0.18和0.15。当细胞外钾浓度从3.5 mM升高至8.5 mM时，CA1皮层的EVF可逆性降低了30%，这是一种诱导CA1自发性电图癫痫发作的方法。因此，海马体细胞外空间的性质存在区域性变化，这可能是CA 1区在缺血后发生癫痫发作和遭受损伤的倾向的基础。
The factors responsible for the unusual susceptibility of the hippocampus to seizures and ischemic cell damage are not well understood. The CA1 pyramidal subfield of the hippocampus is particularly vulnerable to seizure activity and damage after ischemia. The possibility was examined that regional differences exist in extracellular volume, which might influence neuronal excitability and response to injury in the hippocampus. CA1 stratum pyramidale exhibited an exceptionally low extracellular volume fraction (EVF) of 0.12, whereas the EVFs of CA3 and dentate were considerably higher, 0.18 and 0.15, respectively. The EVF of CA1 stratum pyramidale was reversibly reduced by 30 percent when the extracellular potassium concentration was raised from 3.5 to 8.5 mM, a procedure that induced spontaneous electrographic seizures in CA1. Thus there are regional variations in the properties of the extracellular space in the hippocampus that might underlie the propensity of the CA1 region to develop seizures and to suffer damage after ischemia.