发育期大鼠高热惊厥脑损伤模型的建立

The establishment of brain damage model for febrile convulsion in developing rats

目的 :建立发育期大鼠高热惊厥脑损伤模型。方法 :采用热水浴诱导大鼠高热惊厥 (febrileconvulsion ,FC) ,隔日诱导惊厥 1次 ,共诱导 10次。发育期大鼠随机分为 3组 :4 5 .0℃热水浴组 (n =6 ) ,4 4 .5℃热水浴组(n =10 ) ,4 4 .0℃热水浴组 (n =10 ) ,选取高热未惊厥与FC比例最合适的一组 ,将此组的水浴温度定为以后实验的高热处理温度。发育期大鼠随机分为两组 :37.0℃水浴正常对照组 (n =10 ) ,4 4 .5℃热水浴组 (n =4 0 ) ,高热处理组又分为高热未惊厥组 (FC =0 ,n =10 )和FC组 (FC≥ 6次 ,n =2 2 )。HE染色观察各组大鼠海马神经元形态学改变 ;尼氏染色观察海马神经元丢失情况 ;电镜观察海马神经元超微结构的改变 ;体视学方法计数海马CA1区神经元数密度。结果 :HE染色可见FC组海马CA1区、CA2区细胞排列紊乱、极向不清、细胞空泡变 ,细胞核大小不一致、圆形或椭圆形 ;尼氏染色未见FC组明显的海马神经元丢失 ;FC组大鼠海马CA1区和门区神经元线粒体体积减少、部分出现空泡、基质浓缩、嵴模糊不清或消失 ,高尔基复合体轻 中度扩张 ;FC组大鼠海马CA1区神经元数密度显著减少 ,与正常对照组及高热未惊厥组比较 ,差异均有显著性。结论 :热水浴诱导大鼠FC与人类FC有许多相似之处 ,大鼠FC频繁发作可导致海马?

SUMMARY Objective: To establish a brain damage model for febrile convulsions (FC) in developing rats. Methods: FC in rats was induced ten times, once every 2 days. In a bath of warm water, developing rats were randomly divided into three groups: 45.0 ℃ water treated group( n =6), 44.5 ℃ water treated group( n =10), and 44.0 ℃ water treated group( n =10).One group was selected, in which the ratio between none FC and FC was best, and the temperature of this group was determined for following experiments; Developing rats were randomly divided into two groups: 37.0 ℃ water treated group( n =10),and 44.5 ℃ water treated group( n =40).The latter was further divided into none FC (FC=0, n =10) and FC (FC ≥6, n =22) groups. Hippocampal neurons were observed with HE stain; Hippocampal neuron loss was observed with thionine stain; The ultrastructural changes of the hippocampal neurons were observed under the electron microscope, and the numerical density of the hippocampal CA1 neurons was counted by means of the dissector system. Results: With HE stain, the arrangement of hippocampal neurons in CA1 and CA2 was in disorder, polarity was in not clear, vacuolization appeared, and the shape of cell nucleus was elliptic or rounded; With thionine stain, there was not obvious loss of hippocampal neurons in the FC group; In the hippocampal CA1 and hile neurons of FC rats, the mitochondria volume decreased, the matrix condensed, the ridge obscured or disappeared, and vacuoles formed in some mitochondria. Mild to moderate dilation of Golgi′s complex was also observed. Neuronal numerical density (Nv) in hippocampal CA1 in FC group significantly decreased as compared with that in normal and none FC groups. Conclusion: There are many similarities between warm water induced FC in rats and FC in humans, recurrent FC in rats may cause damage and loss of hippocampal neurons in the developing rats, therefore, this model is ideal for the study of brain damage and mechanism for FC.