In vivo intracellular analysis of granule cell axon reorganization in epileptic rats
In vivo intracellular analysis of granule cell axon reorganization in epileptic rats
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DOI：
10.1152/jn.1999.81.2.712
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发表时间：
1999-02-01
影响因子：
2.5
通讯作者：
Dudek, FE
中科院分区：
文献类型：
--
作者：
Buckmaster, PS;Dudek, FE
在红藻氨酸诱导的癫痫大鼠的体内细胞内记录和标记，以解决颞叶癫痫颗粒细胞轴突重组的问题。单个标记的颗粒细胞进行三维重建，并在其整体。与对照组相比，癫痫大鼠的颗粒细胞具有较长的平均轴突长度，在齿状回的所有层，包括门的差异是显着的。在癫痫大鼠中，至少三分之一的颗粒细胞将异常轴突侧支延伸到分子层中。轴突预测到分子层有一个平均总和长度为1毫米每细胞和跨越600 μ m的septotemporal轴的campus的距离内的正常跨度的颗粒细胞轴突侧支。这些体内研究结果证实了先前体外研究的结果。令人惊讶的是，癫痫大鼠中有12%的颗粒细胞，而对照组中没有，将基底树突延伸到门部，为反复兴奋提供了另一条途径。与经常性兴奋一致，癫痫大鼠的许多颗粒细胞（56%）显示叠加在正常抑制性突触后电位上的长潜伏期去极化。这些研究结果表明，癫痫性海马损伤后发生在单细胞水平的变化，可能导致新的，局部的，复发的电路。
In vivo intracellular recording and labeling in kainate-induce depileptic rats was used to address questions about granule cell axon reorganization in temporal lobe epilepsy. Individually labeled granule cells were reconstructed three dimensionally and in their entirety. Compared with controls, granule cells in epileptic rats had longer average axon length per cell; the difference was significant in all strata of the dentate gyrus including the hilus. In epileptic rats, at least one-third of the granule cells extended an aberrant axon collateral into the molecular layer. Axon projections into the molecular layer had an average summed length of 1 mm per cell and spanned 600 mu m of the septotemporal axis of the hippocampus-a distance within the normal span of granule cell axon collaterals. These findings in vivo confirm results from previous in vitro studies. Surprisingly, 12% of the granule cells in epileptic rats, and none in controls, extended a basal dendrite into the hilus, providing another route for recurrent excitation. Consistent with recurrent excitation, many granule cells (56%) in epileptic rats displayed a long-latency depolarization superimposed on a normal inhibitory postsynaptic potential. These findings demonstrate changes, occurring at the single-cell level after an epileptogenic hippocampal injury, that could result in novel, local, recurrent circuits.