衰老脑海马CA1区突触结构的可塑性变化

PLASTIC CHANGES OF SYNAPTIC STRUCTURE IN HIPOCAMPAL CA 1 AREA OF AGED RATS

用E-PTA负染色和锇酸(O_3 O_4)处理普通透射电镜方法结合形态计量和体视学分析年青(3个月)和老年(27个月)SD大鼠海马CA1区分子层突触结构,结果显示衰老时海马CA1区突触形态结构发生了一系列退行性和代偿性变化:单位体积的突触数量(Nv),突触连接带总面积(Sv)明显减少,突触前终末内突触囊泡、线粒体数亦明显减少。突触后膜致密物厚度变薄,而突触接触带的平均长度则代偿性增大。突触间隙宽度,突触前终末剖面积,突触后终末棘器数无明显改变。本文对衰老时海马CAI区突触数量和结构的变化与老年性记忆减退的关系进行了讨论。

Boths of the morphometric and stereological studies have been carried out on E-PTA and O5O4 stained synaptic junction in the hippocampal CA1 area of young (3 months) and old rats (27 months). The number of synapses and the total areas of the synaptic contact zone in a unit volume, the number of the synaptic vesicles and mitochondria, the thickness of postsynaptic dense significantly decrease respectively in aged rats. There were not changes in the average area of presynaptic and postsynaptic terminals and the cleft width of synapses. The average length of synaptic contact zone increase. The present study demonstrates that there were aged-related synapse loss and the plastic change of synaptic structure in hippocampal CA1 area of aged rats. The data suggest that it is the most important for the prevention and therapy of brain aging to try to enhance synaptic plasticity.