伽玛刀对红藻酸致痫大鼠学习记忆能力的影响

Effect of gamma knife radiosurgery on learning-memory ability in kainic acid induced epileptic rats

目的:通过对红藻酸致痫大鼠动物模型的伽玛刀照射,探讨伽玛刀抗痫效果以及对大鼠学习记忆能力的影响.方法:癫痫模型大鼠成功后第6日进行伽玛刀照射.伽玛刀照射后应用临床观察和EEG证实行为学和发作的改变;Morris水迷宫定位航行试验和空间搜索试验测定并对比A,B,C,D各组动物学习记忆能力的变化.观察7,14,21,35,49,63d6个时间点.结果:C组大鼠在伽玛刀照射后21～49d发作次数减少(P<0.05);D组在伽玛刀照射后21～35d发作次数减少(P<0.05).寻找平台潜伏期的时间B,C,D各组成绩均较A组差,但组间相比较无统计学差异(P>0.05).空间搜索试验中B,C,D各组大鼠对平台位置的记忆能力均较A组差(P<0.05),以B,D两组显著.结论:在红藻酸致痫大鼠模型中,40Gy和80Gy伽玛刀照射均可以控制癫痫发作.各组大鼠在水迷宫中记忆能力下降,下降程度与发作频率以及高剂量照射有关.

AIM： To analyze the effects of gamma knife radiosurgery （GKS） on epilepsy and learning-memory ability, in epileptic rats induced by kainic acid （KA）. METHODS： After epilepsy was confirmed by observation of the seizure pattern and electroencephalography （EEG）, gamma knife was performed on the 6th day after injection. Serial seizure and behavior changes were determined through EEG examination and clinical observation. The learning and memory abilities of each group were tested by Morris water maze task involving train of place navigation （ escape latency） and spatial probe test at interval day 7, 14, 21, 35, 49, 63. RESULTS： The clinically observed and EEG-defined seizures were markedly reduced in rats of each radiosurgical group. A significant reduction was noted in group C on day 21 -49, and in group D on day 21 -35 （P 〈0.05）. The escape latencies in group B, C, D were prolonged as compared with the original platform of group B, C, D and were fewer than those of Group A, but there was no difference between each group （ P 〉 0.05 ）. In the spatial probe test, the memory ability for platform position was poorer in group B, C, D, specially group B, D, than in group A. CONCLUSION： In a kainic acid induced epileptic rat model, 40 Gy and 80 Gy GKS can limit seizure. The memory ability of rats can be impaired by KA and GKS. The extent is associated with seizure frequency and irradiation dose.