Epilepsy-induced decrease of L-type Ca2+ channel activity and coordinate regulation of subunit mRNA in single neurons of rat hippocampal 'zipper' slices
Epilepsy-induced decrease of L-type Ca2+ channel activity and coordinate regulation of subunit mRNA in single neurons of rat hippocampal 'zipper' slices
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DOI：
10.1016/s0920-1211(00)00199-6
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发表时间：
2001-03-01
影响因子：
2.2
通讯作者：
Slevin, JT
中科院分区：
文献类型：
--
作者：
Blalock, EM;Chen, KC;Slevin, JT
L型电压敏感性钙通道（VSCC）优先调节被认为在癫痫发生中重要的几种神经元过程，包括缓慢后超极化（AHP）。LTP和营养因子基因表达。然而，目前对L型VSCC在癫痫发生过程中的作用知之甚少。这里.我们使用细胞贴附贴片记录技术和单细胞mRNA分析来研究来自内鼻点燃大鼠的部分分离（拉链）海马切片的CA 1神经元中的L型VSCC。在点燃后1.5-3个月，L型Ca 2+通道活性降低> 50%。记录后，提取并收集相同的单个神经元，使用最近开发的方法进行mRNA分析，该方法不会切断主要的树突状突起。因此，神经元含有基本上完整的mRNA。对于每个收集的神经元，L型孔形成α（1D）/钙1，3-亚基和钙调蛋白的mRNA含量，然后通过半定量动力学RT-PCR分析。L-型α（1D）-亚基mRNA与单个细胞的L-型Ca 2+通道活性相关，而钙调素mRNA则不相关。因此，这些结果似乎提供了第一个直接的证据：单通道和基因表达水平，慢性表达的一个确定的钙离子通道类型是由癫痫样活动调制。此外，目前的数据表明，α（1D）-基因表达的下调点燃可能有助于癫痫样活动的肺长期维护的假设，可能通过减少钙依赖性AHP和/或改变其他相关基因的表达。(C)2001 Elsevier Science B. V.保留所有权利。
L-type voltage-sensitive Ca2+ channels (VSCCs) preferentially modulate several neuronal processes that are thought to be important in epileptogenesis, including the slow after hyperpolarization (AHP). LTP, and trophic factor gene expression. However, little is yet known about the roles of L-type VSCCs in the epileptogenic process. Here. we used cell-attached patch recording techniques and single cell mRNA analyses to study L-type VSCCs in CA1 neurons from partially dissociated (zipper) hippocampal slices from entorhinally-kindled rats. L-type Ca2+-channel activity was reduced by > 50%, at 1.5-3 months after kindling. Following recording, the same single neurons were extracted and collected for mRNA analysis using a recently developed method that dues not amputate major dendritic processes. Therefore, neurons contained essentially full complements of mRNA. For each collected neuron, mRNA contents for the L-type pore-forming alpha (1D)/Ca1,3-subunit and for calmodulin were then analyzed by semiquantitative kinetic RT-PCR. L-type alpha (1D)-subunit mRNA was correlated with L-type Ca2+-channel activity across single cells, whereas calmodulin mRNA was not. Thus, these results appear to provide the first direct evidence at the:;ingle channel and gene expression levels that chronic expression of an identified Ca2+-channel type is modulated by epileptiform activity. Moreover, the present data suggest the hypothesis that down regulation of alpha (1D)-gene expression by kindling may contribute to the lung-term maintenance of epileptiform activity, possibly through reduced Ca2+-dependent AHP and/or altered expression of other relevant genes. (C) 2001 Elsevier Science B.V. All rights reserved.