Spine loss in experimental epilepsy: Quantitative light and electron microscopic analysis of intracellularly stained CA3 pyramidal cells in hippocampal slice cultures
Spine loss in experimental epilepsy: Quantitative light and electron microscopic analysis of intracellularly stained CA3 pyramidal cells in hippocampal slice cultures
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DOI：
10.1016/0306-4522(95)00379-w
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发表时间：
1996-01-01
期刊：
影响因子：
3.3
通讯作者：
Frotscher, M
中科院分区：
文献类型：
--
作者：
Drakew, A;Muller, M;Frotscher, M
癫痫活动引起的神经元改变的顺序知之甚少。在一些癫痫患者的海马中，在门区域和CA3中存在某些神经元类型的损失。在此之前，这种变性的神经元的改变可能会影响synaptic structures.在这里，我们已经估计了树突棘，海马神经元的主要突触后元素，在确定的树突状节段（胞内染色）CA3锥体神经元在海马的“癫痫”切片培养和对照cultures。从5或6天大的幼鼠制备切片培养物，并在体内维持23天，然后通过应用惊厥剂荷包牡丹碱和印防己毒素诱导癫痫活动3天。单个CA3锥体神经元，然后用辣根过氧化物酶细胞内注射，和树突棘的数量进行了计数，在proximodistal树突节应用壳法。此外，还测量了树突的总长度，并评估了分支指数。在"癫痫"培养物中，发现CA 3锥体细胞树突上的棘的数量减少了40%。这种脊柱损失影响近端和周边树突状节段的CA3锥体神经元在类似的程度。在树突长度或分支指数方面，对照组和"癫痫"组之间没有观察到显著差异。定量电子显微镜分析没有发现"癫痫"文化和对照文化之间的差异，在标记的CA3锥体细胞的脊柱区域，表明有一个真实的脊柱损失，而不仅仅是减少的spines.We的结论是癫痫活动的原因在定义的突触后室海马锥体细胞在这些条件下生存的形态学改变。
The sequence of neuronal alterations resulting from epileptic activity is poorly understood. In the hippocampus of some epileptic patients, there is a loss of certain neuronal types in the hilar region and in CA3. The neuronal alterations preceding this degeneration probably affect synaptic structures.Here we have estimated the number of dendritic spines, major postsynaptic elements of hippocampal neurons, in defined dendritic segments of identified (intracellularly stained) CA3 pyramidal neurons in ''epileptic'' slice cultures of hippocampus and in control cultures. Slice cultures were prepared from five-or six-day-old rat pups and maintained in vivo for 23 days before epileptic activity was induced by application of the convulsants bicuculline and picrotoxin for three days. Individual CA3 pyramidal neurons were then intracellularly injected with horseradish peroxidase, and the number of dendritic spines was counted in proximodistal dendritic segments by applying the Shell method. In addition, the total dendritic length was measured and the branching index evaluated.The number of spines on CA3 pyramidal cell dendrites in the ''epileptic'' cultures was found to be decreased by 40%. This spine loss affected proximal and peripheral dendritic segments of the CA3 pyramidal neurons to a similar extent. No significant differences were observed between control and ''epileptic'' cultures in dendritic length or in the branching index. Quantitative electron microscopic analysis did not reveal differences between ''epileptic'' cultures and control cultures in the spine area of the labelled CA3 pyramidal cells, indicating that there was a real spine loss, not just a reduction in the size of the spines.We conclude that epileptic activity causes morphological alterations in defined postsynaptic compartments of hippocampal pyramidal cells surviving under these conditions.