Brain Cell Injuries and Behavioral Changes in Rats with Kernicterus

doi:10.3969/j.issn.1006-9771.2016.06.004

Abstract：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 10μg/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.