缺氧缺血性脑病新生大鼠发育期间海马神经元的变化与康复

目的探讨缺氧缺血性脑病新生大鼠发育期间海马神经元的变化与康复之间的关系。方法采用7日龄Wistar仔鼠,实验组制作缺氧缺血性脑病模型。采用形态学和形态计量学、突触体素免疫组织化学及学习记忆能力测试的方法,对生后7d到2个月,分8个时段对海马CA1区细胞形态及免疫反应阳性物质进行动态观察,对4周和2个月仔鼠进行学习记忆能力测试。结果随增龄对照组大鼠CA1区神经元数量有所减少,但突触体素阳性反应物吸光度值相对升高。实验组CA1区细胞质量明显降低,伴学习记忆能力降低,但与上一实验组比较,随增龄突触体素阳性反应物吸光度值升高(7d与72h比较t=2.012,P<0.05;2周与7d比较t=2.014,P<0.05;3周与2周比较,t=2.716,P<0.01;4周与3周比较,t=2.011,P<0.05)。结论海马区细胞减少、轴突溃变、突触损失是神经功能障碍的病理基础。早期干预可提高神经元的质量,促进神经系统功能发育。

The changes and rehabilitation of neurons in hippocampus of newborn rats with hypoxic-ischemic brain damage during early stage of development

Objective To study the changes and rehabilitation of neurons in hippocampus of newborn rats with hypoxic-ischemic brain damage (HIBD) during their early stage of development. Methods Objects were seven days old Wistar neonatal rats with HIBD. The morphology, morphometry and immunohistochemically expression of synaptophysin were studied. Their dynamic changes were followed from postnatal day 7 to 2 month in 8 separate intervals. Their ability of learning and memory were tested at 4 week and 2 month of age. Results In control group with aging, neurons in hippocampus CA1 area underwent physiologic death by decreasing in cell numbers; the optical density of synaptophysin positive products increased. The neurons and the ability of learning and memory in experimental group decreased significantly; the optical density of synaptophysin positive products increased in 7 days, 2 weeks, 3 weeks and 4 weeks time spots compared with 72 hours, 7 days, 2 weeks and 3 weeks respectively in experimental group (7 d vs. 72 h, P<0.05; 2 w vs. 7 d, P<0.05; 3 w vs. 2 w, P<0.01; 4 w vs. 3 w, P<0.05). Conclusions HIBD affects learning and memory in rats during their developmental stages. The pathology of the neurological damages is cell damaging, axon degeneration and synapses losing. Early intervention can increase quality of neurons and improve development of nervous system.