摘要
目的 探讨不同日龄的新生大鼠缺血缺氧脑损伤后早期认知功能的改变.方法 选取SD新生大鼠46只,按照后期测试时间的不同,分为21日龄的大鼠23只（21日龄组）,31日龄的大鼠23只（31日龄组）,2组按照随机数字标法根据是否制备缺氧缺血模型分成21日龄造模组12只,21日龄假手术组11只,31日龄造模组12只,31日龄假手术组11只.采用改良Rice模型方法将21日龄造模组和31日龄造模组制成新生期大鼠早期认知功能障碍模型,假手术组均模拟皮肤切开分离颈总动脉,但不结扎,无缺氧.4组大鼠造模成功后采用Morris水迷宫测试空间定位学习能力及空间记忆水平.结束水迷宫测试后断头取脑,进行电镜及尼氏染色观察脑组织细胞形态及尼氏小体定量-神经细胞活力分析.结果 经Morris 水迷宫实验发现,21日龄造模组和21日龄假手术组平均逃避潜伏期均明显落后于31日龄造模组和31日龄假手术组,差异有统计学意义（P＜0.05）,另2个造模组平均逃避潜伏期亦明显落后于相应的假手术组,差异有统计学意义（P＜0.05）.4组大鼠的平均穿台次数和平均台周Ⅰ区活动时间比较,差异均无统计学意义（P＞0.05）,而21日龄造模组平均台周Ⅰ区活动路程明显低于21日龄假手术组,差异有统计学意义（P＜0.05）,同时21日龄2组大鼠的平均台周Ⅰ区活动路程明显低于相应的31日龄2组大鼠,差异有统计学意义（P＜0.05）.31日龄造模组平均台周Ⅰ区活动路程亦明显低于31日龄假手术组,差异有统计学意义（P＜0.05）.电镜观察显示,2个假手术组缺血侧的海马组织神经细胞结构正常,突触前膜内少见线粒体,2个造模组神经细胞有不同程度核固缩表现及内质网扩张等,海马突触内见较多线粒体.经尼氏小体定量-神经细胞活力分析发现,2个造模组的右大脑皮质活力较相应的假手术组显著下降,差异有统计学意义（P＜0.01）;31日
Objective To establish an early cognitive disorder model in rats and investigate the early cognitive functioning after ischemic hypoxic brain injury during the neonatal period. Methods Forty-six newborn Sprague-Dawley rats were randomized into a 21-d-old group and a 31-d-old group. These 2 groups were then subdivided into model and sham-operated subgroups （M21, n=12; SH21, n=11; M31, n=12; SH31, n=11）. A model of neonatal early cognitive disorder was established in the rats of the M21 and M31 groups using a modification of Rice＇s method. Rats in the SH21 and SH31 groups received skin incisions and common carotid artery separation without ligation or hypoxia. Each group was tested with a Morris water maze. The rats were sacrificed after testing, and brain tissue was examined under the electron microscope. Nissl staining allowed Nissl body quantification and neurocyte acin the M21 group was significantly longer than in the SH21 group. The 31-d-old subgroups had shorter average escaping latencies than the corresponding 21-d-old subgroups. （b） Spatial memory： The average platform times, Ⅰ region times and Ⅰ region distances showed no significant differences among groups. ②Brain pathology （a） Gross appearance： Obvious ischemic hemisphere atrophy was observed in the M group, and no abnormality was observed in the SH group. （b） Electron microscopic observation： In the SH group cell ultrastructures in the ischemic hippocampus were normal. Karyopyknosis and dilated endoplasmic reticulums were found in the M group. More mitochondria were found in the presynaptic membranes of the ischemic hippocampus in the M group than that in the SH group. （c） Nissl body quantification and neurocyte activity analysis： Significantly less activity in the ischemic cortex was found in the M21 group compared to the SH21 group. More activity was observed in the 31-d-old subgroups than in the corresponding 21-d-old subgroups. Conclusions ①The neonatal rats with ischemic hypoxic brain injury had prolonged ave
出处
《中华物理医学与康复杂志》
CAS
CSCD
北大核心
2010年第10期725-729,共5页
Chinese Journal of Physical Medicine and Rehabilitation
基金
浙江省教育厅项目（20020448）,浙江省科技厅钱江人才计划项目（2009R10024）
