惊厥阈下脑放电对大鼠海马突触长时程增强影响的研究

The effect of subthreshold stimulation on hippocampal long-term potentiation in rats

目的 研究反复的阈下脑放电损伤认知功能的机制。方法 在大鼠前额叶皮层给予电刺激 ,建立惊厥阈下脑放电的动物模型 ,研究阈下脑放电对大鼠海马突触长时程增强 (LTP)的影响。结果 前额叶皮层电刺激可引起皮层及海马的惊厥阈下放电。持续 3min的放电可短时间抑制在海马齿状回建立的LTP ,这种抑制现象在停止刺激 5min后消失。结论 LTP抑制是阈下放电损伤短时记忆功能的机制之一。此机制可能和N -甲基天冬酸 (NMDA)

Objective In order to investigate the mechanism in which cognitive function was impaired by frequent subthreshold electric stimulation.Method The animal model of subthreshold convulsant cerebral discharges (SCD) were initiated by giving subthreshold electrlc stimuli(SES) to the anterior frontal cortex of the rats, which induced epileptiform EEG discharges but no seizures and to investigate the effect of SCD on long-term potentiation(LTP).Results The anterior frontal cortex SES caused SCD in cortex and hippocampus. Continuous SCD discharges lasting 3 minutes, temporally suppressed LTP established in dentate gyrus, and this suppression disappeared since stimuli had been discontinued for 5 minutes.Conclusion LTP suppression is one of the mechanisms of short-term memory function impaired by sub-convulsant discharges which may be related to N-Methyl-D-aspartota-receptor channel abnormally continuous opening and excessive accumulation of intracellular Ca 2+ .