Taylor C P, Krnjević K, Ropert N
Neuroscience. 1984 Jan;11(1):101-9. doi: 10.1016/0306-4522(84)90216-1.
In experiments on rats under urethane anaesthesia--in which the fimbria and hippocampal commissure had been cut previously to eliminate orthodromic inputs--the negative antidromic population spike evoked in CA3 by fimbrial stimulation was measured inside and outside 73 neurons in the stratum pyramidale. Subtraction of the extracellular from the intracellular records showed that on the average 39.2% (S.E. 1.93) of the extracellular population spikes appeared as a positive, depolarizing transmembrane potential. Similar measurements in the dendritic zone of CA3, where the extracellular antidromic population spike is positive, revealed a smaller and hyperpolarizing transmembrane potential, whereas presumed neuroglia showed no consistent transmembrane potential in either direction. Further tests demonstrated clear facilitation of individual pyramidal cell firing, synchronous with the antidromic population spike. These observations are consistent with the possibility that, owing to the unusually close packing and regular alignment of the pyramidal neurons, electrical field interactions in CA3 tend to promote synchronized mass discharges.
在对接受氨基甲酸乙酯麻醉的大鼠进行的实验中——此前已切断海马伞和海马连合以消除顺行输入——在锥体层的73个神经元内部和外部测量了由海马伞刺激在CA3区诱发的负向逆向群体峰电位。细胞内记录减去细胞外记录显示，平均而言，39.2%（标准误1.93）的细胞外群体峰电位表现为正向、去极化的跨膜电位。在CA3区的树突区域进行的类似测量显示，细胞外逆向群体峰电位为正时，跨膜电位较小且为超极化，而推测的神经胶质细胞在两个方向上均未显示出一致的跨膜电位。进一步的测试表明，单个锥体细胞的放电明显增强，与逆向群体峰电位同步。这些观察结果与以下可能性一致：由于锥体细胞异常紧密的排列和规则的对齐，CA3区的电场相互作用倾向于促进同步的大量放电。
