REMODELING OF SYNAPTIC ARCHITECTURE DURING HIPPOCAMPAL KINDLING
REMODELING OF SYNAPTIC ARCHITECTURE DURING HIPPOCAMPAL KINDLING
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DOI：
10.1073/pnas.85.9.3260
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发表时间：
1988-05-01
影响因子：
11.1
通讯作者：
DETOLEDOMORRELL, L
中科院分区：
文献类型：
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作者：
GEINISMAN, Y;MORRELL, F;DETOLEDOMORRELL, L
“点燃”现象与突触传递的持久促进有关。这种促进的可能机制可能涉及突触接触数量的变化。然而，之前试图证明突触形态改变可以解释点燃的长期影响的尝试失败了，这可能是由于当时缺乏无偏的突触定量方法。使用无偏立体解剖技术，我们估计了通过植入电极对内侧穿通路径进行电刺激而点燃的大鼠海马齿状回中分子层中每个神经元的突触数量。未点燃但受到刺激（库仑控制）和未刺激但植入的大鼠作为对照。在达到五次全身性癫痫发作的触发标准后 4 周，对动物进行编码并处死。当对具有连续或不连续突触后密度（“非穿孔”或“穿孔”突触）的轴棘突触进行差异分析时，获得了最重要的结果。点燃导致非穿孔突触接触的选择性丧失，而不是穿孔突触接触的保留。此外，相对于未刺激或库仑对照组，点燃大鼠中穿孔突触与非穿孔突触的比例分别增加了 45% 或 40%。这些发现表明，突触功效可能取决于两种突触类型的平衡。选择性消除非穿孔突触可能会增强剩余突触接触的效力，这一过程让人想起发育过程中的突触重塑。
The "kindling" phenomenon is associated with long-lasting facilitation of synaptic transmission. A possible mechanism of such facilitation could involve changes in the number of synaptic contacts. However, previous attempts to demonstrate a synaptic morphological alteration that could account for the long-term effects of kindling had failed, possibly due to the unavailablity, at the time, of unbiased methods for synapse quantitation. Using the unbiased stereological disector technique, we estimated the number of synapses per neuron in the middle molecular layer of the hippocampal dentate gyrus in rats kindled by electrical stimulation of the medial perforant path with implanted electrodes. Unkindled but stimulated (coulombic control) and unstimulated but implanted rats served as controls. Animals were coded and killed 4 weeks after reaching the kindling criterion of five generalized seizures. The most important results were obtained when axospinous synapses with continuous or discontinuous postsynaptic densities ("nonperforated" or "perforated" synapses) were differentially analyzed. Kindling resulted in a selective loss of nonperforated synaptic contacts in contrast to preservation of perforated ones. Furthermore, the ratio of perforated to nonperforated synapses was increased by 45% or 40% in kindled rats relative to unstimulated or coulombic controls, respectively. These findings suggest that synaptic efficacy may depend on a balance of the two synaptic types; selective elimination of nonperforated synapses may augment the potency of remaining synaptic contacts, a process reminiscent of synaptic remodeling during development.