核黄疸模型大鼠脑细胞损伤及行为学后遗症的研究

Brain Cell Injuries and Behavioral Changes in Rats with Kernicterus

目的探讨核黄疸模型大鼠脑细胞损伤及行为学改变情况。方法 25只5日龄Sprague-Dawley大鼠随机分为对照组(n=11)和模型组(n=14)。模型组予小脑延髓池内注射胆红素溶液10μg/g,对照组注射等量生理盐水。观察注射后大鼠的神经行为变化,并记录其体质量;建模后第1天予TUNEL法观察模型组(n=3)脑基底节纹状体神经细胞凋亡情况;余下大鼠均在生后19 d行步态分析及横木行走测试,30 d行水迷宫实验。结果模型组出现明显神经行为异常,如握拳、角弓反张,且体质量显著低于对照组(F>27.707,P<0.001)。TUNEL染色示模型组基底节纹状体神经细胞凋亡。步态分析中,模型组左右后肢步长均短于对照组(t>4.129,P<0.01),步长差值显著大于对照组(t=-4.415,P<0.001),但步宽与对照组无显著性差异(t=0.462,P=0.649)。横木行走测试中,模型组得分明显低于对照组(t=-3.644,P=0.004)。Morris水迷宫实验中,模型组各时间点逃避潜伏期均长于对照组(F>6.206,P<0.05);穿越平台次数少于对照组(t=3.297,P=0.004)。结论核黄疸模型大鼠具有多项运动功能异常和学习记忆障碍,可分别使用步态分析、横木行走测试及水迷宫实验进行评价。

Objective To study the brain cell injuries and behavioral changes of newborn rats with kernicterus. Methods Twenty-five 5-day-old Sprague-Dawley rats were divided into control group （n=11） and model group （n=14） radomly. The model group was injected with bilirubin solution 10 μg/g in the cisterna magna, while the control group was injected with equal volume of normal saline. The neurobe- havioral changes were observed and the body mass were recorded. TUNEL staining was used to check the apoptosis of striatal nerve cells of basal ganglia in the model group （n=3） on the first day after modeling. The remaining rats were assessed by gait analysis and beam-walking test 19 days after birth, and Morris water maze test was performed 30 days after birth. Results The model group showed apparently abnor- mal neurobehavioral changes, such as clenched fists, opisthotonos and the body mass were significantly lower in the model group than in the control group （F〉27.707, P〈0.001）. TUNEL staining showed striatal nerve cells apoptosis in the model group. For the gait analysis, the step lengths of both hind legs were shorter （t〉4.129, P〈0.01）, and the difference of step length was longer （t=-4.415, P〈0.001） in the model group than in the control group, however, there was no significantly difference in the step width between two groups （t=0.462, P=0.649）. For the beam-walking test, the score was lower in the model group than in the control group （t=-3.644, P=0.004）. For the Morris water maze test, the escape latency was longer （F〉6.206, P〈0.05）, and the number of crossing platform was less （t=3.297, P=0.004） in the model group than in the control group. Conclusion The newborn rats＇ model of kernicterus showed deficits in multiple motor functions and learn- ing and memory ability, which could be assessed by gait analysis, beam-walk test and Morris water maze test, respectively.