微波照射对大鼠在体海马诱发电位长时程增强的影响  

EFFECTS OF MICROWAVE IRRADIATION ON HIPPOCAMPALLONG-TERM POTENTIATION (LTP) IN VIVO IN RATS

作　　者：彭晓东[1] 刘传缋[1] 赵亚丽[2] 马洪波[2] 蒲京隧[2] 

机构地区：[1]军事医学科学院毒物药物研究所,北京100850 [2]航天医学工程研究所,北京100094

出　　处：《生物物理学报》2001年第2期371-378,共8页Acta Biophysica Sinica

摘　　要：海马诱发电位长时程增强现象 (Long-term potentiation,LTP) ,常被用来研究与突触可塑性密切相关的学习与记忆过程的分子机制。为了研究微波照射对海马突触可塑性的影响 ,采用海马齿状回诱发电位的群峰电位幅度 (theamplitudeofpopulationspikes ,PSamplitude)和群体兴奋性突触后电位的始段上升斜率 (theinitialslopeofthe populationexcitatorypostsynapticpotentials, pEPSPslope)两个观察指标 ,观察10mW/cm2 ,15mW/cm2和25mW/cm2三个强度 ,2450MHz微波照射对乌拉坦麻醉大鼠在体海马齿状回诱发电位和LTP的影响。结果表明 ,每天1小时 ,连续7天的慢性连续型2450MHz微波照射阻碍麻醉大鼠在体海马齿状回LTP的产生 ,并使LTP的幅度减小。提示微波照射造成学习记忆的损害 ,可能是通过阻碍海马LTP的产生来实现的。Long-term potentiation (LTP) of hippocampal synaptic activity is the most popular and widely used model of synaptic plastic changes, which is considered to be related to learning and memory. In order to investigate the effects of microwave irradiation on the hippocampal synaptic plasticity, LTP of the population spikes amplitude (PS amplitude) and the initial slope of the population excitatory postsynaptic potential (pEPSP slope) were examined immediately after the chronic microwave irradiation on rats. LTP was induced in hippocampal dentate gyrus by delivering weak tetanus stimulation (WTS: 60Hz 30 pulses) or strong tetanus stimulation (STS: 10 burst of 5 pulses, pulses frequency 400Hz, inter-burst interval 200ms) to medial perforant path (MPP) of urethane-anaesthetized rats, which had been pretreated by a series of microwave. In the microwave treatment, the rats were exposed to continuous (2450MHz) microwave in seven daily sessions of 60 min at 10 mW/cm2、15 mW/cm2 and 25 mW/cm2 power densities respectively. Control group was treated on the same condition without microwave irradiation. The data show that the continuous 2450MHz microwave can decrease the induce rate of the PS amplitude of LTP by WTS, and can attenuate the magnitude of the PS amplitude of LTP induced by weak or strong tetanus stimulation in power density-dependent manner. The results provide evidence that chronic continuous 2450MHz microwave irradiation can block the induction of LTP in the hippocampal dentate gyrus in vivo. The implication of these results with microwave effect on damage of memory and synaptic plasticity in the hippocampus is probably through the mechanism that microwave can induce attenuation on hippocampal LTP.

关 键 词：微波照射 海马 LTP 学习 记忆 

分 类 号：Q684[生物学—生物物理学] Q426