环境刺激对缺氧缺血性脑损伤新生大鼠学习记忆及海马病理学的影响

Influence of Environment Stimulation on Learning and Memory Ability and Hippocampal Pathology of Neonatal Rats with Hypoxic-Ischemic Brain Damage

目的研究环境刺激对缺氧缺血性脑损伤(HIBD)新生大鼠学习记忆及海马病理学的影响。方法按Rice法制备7日龄SD大鼠HIBD模型。随机分为3组丰富环境(EE)组、贫瘠环境(IE)组和标准环境(SE)组。另设假手术(Sham)组。各组大鼠造模后d1开始分别予不同环境刺激,造模后d28,通过Morris水迷宫实验测试大鼠学习记忆能力,HE染色观察其海马病理形态学变化,尼氏染色计数海马存活神经元数目。结果在学习记忆能力上,EE组成绩明显优于SE组(P<0.01)和IE组(P<0.001),与Sham组相比差异不明显(P>0.05);而SE组显著优于IE组(P<0.01)。HE染色见Sham组左侧海马无异常,EE组左侧海马轻度异常,SE和IE组左侧海马明显异常。神经元尼氏染色计数显示,EE组左侧海马神经元存活数目多于SE组(P<0.05)和IE组(P<0.01),与Sham组差异不明显(P>0.05),SE组显著低于Sham组(P<0.01),明显多于IE组(P<0.05)。结论EE有利于脑损伤修复,对HIBD新生大鼠具有脑保护作用;IE不利于脑损伤修复。

Objective To observe the influence of environment stimulation on learning and memory ability and hippocampal pathology of neonatal rats with hypoxic - ischemic brain damage （HIBD）. Methods The models of HIBD SD rats were established by the method of Rice, and were divided randomly into three groups： enriched environment stimulation group （ EE）, impoverished environment stimulation group （IE）, and standard environment stimulation group （SE）. The sham -operation rats were served as control group. Different environment stimulation was administrated to the rats since day 1 after HIBD. On the day 28, Morris water maze was used to evaluate the learning and memory ability. HE staining and nissl stain were employed to observe the pathological change and the number of neurons in hippocampus of rats. Results The learning and memory ability of EE group was significantly higher than that of SE group （ P 〈 0.01 ） and IE group （ P 〈 0. 001 ）, and there was no significant difference compared EE group with Sham group （P 〉 0.05 ）, and the ability of SE group was higher than that of IE group （ P 〈0.01 ）. The results of HE stain displayed the pathology in left - sided hippocampus of Sham group was normal, and that of EE group was minimal abnormal, while the pathology of SE group and IE group were obviously abnormal. The nissl staining showed that the number of left - sided hippocampal neurons was no significant difference compared EE group with Sham group （ P 〉 0.05 ）. The number of SE group was lower than that of Sham group （ P 〈 0.01 ）, and was significantly more than that of IE group （ P 〈 0.05 ）. Conclusion The study suggests that EE is good for recovery from brain damage and protected brain of rats with HIBD,but IE is not good for it.