幼年大鼠反复热性惊厥对惊厥易感性的远期影响

Long-term effect of repeated febrile convulsions on seizure susceptibility in immature rats

目的 探讨幼年大鼠反复热性惊厥对惊厥易感性的远期影响。方法 利用热水浴诱导惊厥模型 ,诱导 2 2日龄SD大鼠发生 15次热性惊厥。间隔 3个月再用同样的方式诱发惊厥 ,观察大鼠前后两次惊厥发生率、惊厥潜伏期和惊厥持续时间的差异。采用尼氏染色及Timm染色观察神经元损伤和海马结构的变化。结果 有幼年反复热性惊厥史的大鼠 3个月后再次接受热刺激时 ,惊厥发生率 (74 % )较其高热对照组 (8% )高 ,差异有显著性 (χ2 =13 5 0 ,P <0 0 1) ;惊厥持续时间 [(19 3± 5 1)min]较幼年时 [(5 5± 2 9)min]延长 ,差异有显著性 (t=10 4 9,P <0 0 1) ;且再次接受热刺激时 ,有 4只大鼠出现惊厥持续状态 ,而幼年时 ,无 1只大鼠出现惊厥持续状态。尼氏染色幼年大鼠脑内未见神经元丢失 ,3个月后再惊厥大鼠脑内海马CA3 区见明显神经元丢失。Timm染色显示惊厥15次大鼠海马区有明显苔藓纤维发芽现象 ,持续至 3个月后。结论 在未成年大鼠 。

Objective To elucidate the long term effect of repeated febrile convulsions (FC) on seizure susceptibility in immature rats Methods Warm water immersion rat FC model was developed with SD rats 22 days of age, 15 attacks of seizures were induced in the rats every other day, and some of the rats were left un stimulated for 3 months, then were re stimulated Seizure phenomenon was observed, including the latency and the duration of seizures and the temperature of rats Hippocampal neuron loss and mossy fiber sprouting were detected by thionine staining and Timm staining Results After the 15th bath, the latency, the duration of seizures, and the temperature of rats were respectively (4 3±0 8) min, (5 5±2 9) min, (42 2±0 7)℃ Three months later, on re stimulation, in 14 of 19 rats with previous FC experience seizures occurred while in only one of 13 non FC rats seizure occurred and lasted for 8 5 min Three months later,the latency, the duration of seizures, and the temperature of rats were respectively (5 4± 0 6) min,(19 3±5 1) min,and (42 4±0 4)℃(4 rats with status epileptics were not included) The incidence of seizures on re stimulation in rats of FC group (74%) was significantly higher than that in non FC group (8%)(χ 2=13 50, P <0 01), and the duration of seizures [(19 3±5 1) min] was significantly longer than those induced in early life[(5 5±2 9) min]( t =10 49, P <0 01) After the 15th bath, no significant change was demonstrated in rats of different groups While 3 months later, prominent neuron loss was observed in hippocampal CA 3 region in rats with previous FC experience ( P <0 01) Significant mossy fiber sprouting phenomenon was detected after the 15th bath and 3 months later ( P <0 05) Conclusion Repeated FC in early life enhances long term susceptibility of rats to seizure