电磁脉冲辐射致大鼠皮层神经元超微结构损伤效应及对空间学习记忆能力的影响

The effect of electromagnetic pulse on neuronal ultrastructure and the space learning and memory ability in rats

目的:电磁脉冲辐射(electromagnetic pulse,EMP)可以引起中枢神经系统(CNS)损伤和神经行为学的改变。因此,研究EMP对CNS短期的生物学效应具有重要意义。方法:本文通过电子显微镜技术和Morris水迷宫技术,研究了场强为400 kV/m,脉冲为200次的EMP辐射后短时间内对大鼠皮层神经元超微结构及空间学习记忆能力的影响。结果:辐照射后6 h的大鼠皮层神经元超微结构显示,神经元胞核内异染色质增多;核膜有不同程度凹陷、破损及皱缩。胞质内有明显的线粒体肿胀;胞内粗面内质网呈囊性变、脱颗粒。EMP辐射后24 h时,部分神经元出现染色质浓集、边移,甚至细胞核明显皱缩而失去结构,类似凋亡细胞特点,并有凋亡小体出现。Morris水迷宫结果显示,与正常对照组相比,EMP损伤后,大鼠逃避潜伏期明显延长(P<0.05);动物在平台象限停留时间明显缩短(P<0.01)。结论:400 kV/m的EMP可引起大脑皮层神经元超微结构发生损伤,且导致实验动物空间学习记忆能力的下降。

Objective： Electromagnetic pulse （EMP） can cause central nervous system （CNS） damage and neurobe- havioral disorders. To study the biological effects of EMP on CNS may have important applied value. Here we reported that the biological effects of EMP （400 kV/m for 200 pulses） on neuronal ultrastructure and the space learning and mem- ory ability in rats. Methods： The electron microscopic technology and Morris water maze was used to observe the effect of EMP on cerebral cortex neurons. Results ： Electron microscope results showed the ultrastrueture of rat cortical neurons in EMP group 6 h after radiation changed markedly, characterized with nuclear membrane folds, collapses, blurred bounda- ries, nuclear condensation. It also showed obvious swelling of mitochondria in the cytoplasm was as spherical. Moreover, at 24 h after EMP radiation, some cellular cytoplasm concentration happened as electron density increased, nucleus sig-nificantly shrink, chromatin concentration and aggregation at the edge of the nucleus, even apoptotic body also can be seen which were similar to apoptotic ceils. Morris water maze results showed the escape latency was longer in EMP group than it in control group （ P 〈 0.05 ） and time spent in target quadrant was remarkably reduced than control group （ P 〈 0.01 ）. Conclusion： Exposure to 400 KV/m EMP could induce neuronal ultrastructure damaged and affecte the perform- ance of rats in the Morris water maze.