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高低频强直刺激诱导大鼠视皮层长持续长时程增强后突触超微结构的变化

潘斌, 杨东伟, 韩太真

西安交通大学医学院生理学教研室.陕西，西安 710061

摘要

在发育期大鼠视皮层上以2 Hz与100 Hz强直刺激诱导长持续长时程增强（long-lasting long-term potentiation, L-LTP），然后观察突触超微结构的变化。在L-LTP形成后，运用电子显微镜及图像分析技术分析突触形态的变化。实验中观察到，突触界面曲率、突触数密度以及突触后致密物厚度在2 Hz与100 Hz组较对照组均显著增加，而突触间隙宽度减小。在100 Hz强直刺激诱导L-LTP组中，单位体积的活性区面积显著增加。100 Hz强直刺激诱导L-LTP组较2 Hz强直刺激诱导L-LTP组中单个突触活性区的面积大。以上结果表明：100 Hz强直刺激诱导L-LTP组中新形成的突触较2 Hz强直刺激诱导L-LTP组中的突触大，提示100 Hz强直刺激引起的L-LTP可能伴随有突触后细胞骨架蛋白重组或合成的增加。

关键词： 长时程增强; 视皮层; 形态学; 突触

Changes of synaptic structure after long-lasting LTP induced by high and frequency tetanus in slices of the rat visual cortex

Pan Bin, Yang Dongwei, Han Taizhen

Department of Physiology, School of Medicine, Xi'an Jiaotong University.Xi’an 710061,Shaanxi

Abstract

Synaptic ultrastructural changes after long-lasting long-term potentiation (L-LTP) induced by 2 and 100 Hz tetanus were investigated by electron microscopic and stereological approach in slices of the developing rat visual cortex (postnatal days 15-21). Both 2 and 100 Hz tetanus-induced L-LTP groups showed significant increases in synaptic interface curvature, synaptic numeric density and postsynaptic density thickness, as well as significant decreases in the cleft width, as compared with the control groups. In addition, the volume density of the active zone (AZ) was increased significantly in the 100 Hz tetanus-induced L-LTP group, but not in the 2 Hz group. The mean lateral area of individual AZ in the 100 Hz group was relatively higher than that in the 2 Hz group. These data suggest that newly formed synapses in the 100 Hz tetanus-induced L-LTP group are larger than those in the 2 Hz group and that 100Hz tetanus might trigger reorganization or synthesis of postsynaptic cytoskeleton.

Key words: Long-term potentiation;Visual cortex;Morphology;Synapse

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引用本文：

潘斌, 杨东伟, 韩太真. 高低频强直刺激诱导大鼠视皮层长持续长时程增强后突触超微结构的变化[J]. 生理学报 2005; 57 (1): .

Pan Bin, Yang Dongwei, Han Taizhen. Changes of synaptic structure after long-lasting LTP induced by high and frequency tetanus in slices of the rat visual cortex . Acta Physiol Sin 2005; 57 (1): (in Chinese with English abstract).