高原环境对大鼠海马超微结构影响及可塑性的研究

本文采用形态计量方法对从低海拔(397米)移居到高海拔(3416米)一周(急性)、四周(亚急性)及返回到低海拔四周(恢复)的Wistar大鼠海马CA3区的突触、锥体细胞超微结构进行定量研究观察。结果:急性组主要表现为线粒体数量增加,粗面内质网池轻度扩张和脱颗粒。亚急性组海马锥体细胞肿胀、粗面内质网明显分布紊乱、脱颗粒和断裂;核糖体减少,线粒体不同程度肿胀、嵴断裂、数量减少、外膜膨出和变形。髓鞘变性。树突棘中的棘器减少,轴突和树突内的线粒体也发生肿胀、嵴断裂。轴棘、轴树突触间隙宽度变窄(P<0.01)。突触小泡数量减少(P<0.01)。恢复组海马锥体细胞内部分线粒体和粗面内质网仍未完全恢复正常。其它细胞器已恢复正常,突触超微结构恢复正常。本文讨论了高原环境对大鼠海马影响以及返回平原后自然恢复的可能性,并对形态改变的机制进行了探讨。

EFFECT OF HIGH ALTITUDE ON HIPPOCAMPUS ULTRASTRUCTURE AND ITS PLASTICITY STUDY IN RAT

A method of the morphological quantum was used in this study that the synapses in the hippocampus area CA3 with an electronic microscope. The ultrastructure changes of pyramidal cell were observed. By moving rats from lower to higher altitudes for one week (Acute), four weeks (Subacute) and returned to lower altitude for four weeks (Restoration). The experiment resulted in(l)Acute Group:In the pyramidal cells,the rough endoplasmic reticula(RER)swelled and degranulated slightly. The number of the mitochondria increased. (2)Subacute Group:The RER became more dilated with break-up, more degranulation and disorder arrangement. The mitochondria exhibited swelling and crest break-up. The mitochandrial changes were also found in the axons and dendrities. The spine apparatus were reduced in number. The amount of synaptic vesicles showed fewer and the axo-spine and the axo-dendritic width narrow. The statistical differences were significant (P<0. 01). (3)Restoration Group:In the pyramidal cells,part of mitochondria had swollen and crest break-up. The disorder and degranulation of RER existed. The relation between the morphological and the functional alteration in hypoxic nervous system is also disscussed.