Behavioral alterations following a hypoxic-ischemic brain injury in neonatal rats and the effects of treatment with caspase inhibitor.

半胱天酶被认为在大鼠脑缺氧缺血（HI）损伤后的延迟神经元细胞死亡中起关键作用。采用Moris水迷宫试验评估新生儿缺血性损伤后运动和认知功能障碍的特征。此外，我们还研究了caspase抑制剂对HI损伤后认知改变的影响。1)缺氧缺血性脑损伤后的行为改变通过单侧颈动脉结扎和8%氧暴露2小时的联合方法获得7日龄大鼠hi模型动物。这些动物在28天大时进行了水迷宫测试。缺血大鼠与对照组在游泳速度上无显著差异。HI大鼠到达固定平台的平均潜伏期较对照大鼠明显延长，缺血组大鼠无法无差错完成实验。2)组织学表现与学习能力的关系各缺血性动物脑损伤程度不同。计数同侧海马CA1区神经元细胞数量。组织学结果与行为改变程度无统计学意义。3)观察半胱天冬酶抑制剂（BAF）对HI负荷大鼠行为改变的影响。BAF对大鼠学习能力无明显影响。

Caspases are believed to play a key role in the delayed neuronal cell death observed in the rat brain following hypoxic-ischemic (HI) insult. The characterization of motor and cognitive dysfunctions following neonatal ischemic injury was assessed by using Moris water maze test. Furthermore we investigated the effect of caspase inhibitor administration on the cognitive alterations following HI insult.1) Behavioral alterations following a hypoxic-ischemic brain injuryHI model animals were obtained by the combination of monolateral carotid ligation and exposure to 8 % oxygen for 2 hours in 7-day-old rats. The animals were tested in a water maze test at 28 days old. No significant differences were found between ischemic and control rats in the speed of swimming. The average latency for HI rats to reach the fixed platform was significantly prolonged in comparison with control rats, and the ischemic group rats were unable to perform the test without mistakes.2) The relation between the histological findings and learning abilityThe extend of the brain damage was not the same in all ischemic animals. The number of neuronal cells in the ipsilateral hippocampal CA1 region was counted. There was no significant relation between the histological findings and the extend of behavioral alternations statistically.3) The effects of caspase inhibitor (BAF) on the behavioral alternationsBAF was injected intraperitoneally after HI loading. No significant effect in learning ability was observed in BAF treated rats.