宫内缺氧对新生鼠顶叶皮质神经元内nNOS表达及对成年小鼠学习记忆能力的影响

EFFECTS OF HYPOXIA IN UTERUS ON nNOS EXPRESSION IN POSTNATAL MOUSE PARIETAL CORTEX AND THE LEARNING AND MEMORY ABILITY OF ADULT MOUSE

目的探讨孕鼠宫内缺氧对生后小鼠发育时期顶叶皮质神经元内神经性一氧化氮合酶(nNOS)表达及对成年小鼠学习记忆能力的影响。方法用低张性缺氧模型致胎龄13d、15d、17d小鼠宫内缺氧,将新生后P1、P7、P14、P28、P90鼠脑组织作Nissl染色及nNOS免疫组织化学反应,观察顶叶皮质神经元数量、形态及nNOS神经元表达,P90小鼠行Morris水迷宫实验。结果与正常组比较,宫内缺氧组小鼠顶叶皮质神经元数量明显减少(P<0.05),顶叶皮质神经元内nNOS表达明显减弱(P1,P<0.01;P7,P<0.05;P14,P<0.05;P28,P<0.01;P90,P<0.01)。宫内缺氧组小鼠逃避潜伏期延长(1d、2d,P<0.05;3d、4d,P<0.01)及穿环次数明显减少(P<0.05)。结论宫内缺氧导致生后小鼠发育时期顶叶皮质神经元数量明显减少,顶叶皮质神经元内nNOS表达明显减弱;宫内缺氧引起成年小鼠学习记忆能力降低。

Objective To study the effects of hypoxia in uterus on nNOS expression in postnatal mouse parietal cortex and the learning and memory ability of adult mouse. Methods The number and shape of parietal cortex neurons during postnatal development with hypotonic hypoxia in uterus were observed by Nissl staining.The expression of nNOS in parietal cortex neurons during postnatal development with hypoxia in the uterus was studied with immunohistochmistry.The ability to learn and memorize in adult mouse was observed by Morris water maze. Results Compared with the control group,the number of neurons in parietal cortex from mouse during postnatal development in hypoxic group reduced significantly（P〈0.05）and the expression of nNOS in parietal cortex neurons during postnatal development in the hypoxic group decreased significantly（P1,（P〈0.01）;P7,P〈0.05;P14,P〈0.05;P28,P〈0.01;P90,P〈0.01）.The period from latency to escape platform was prolonged（1 day,2 days,P〈0.05;3 days,4 days,P〈0.01）,and the wearing numbers reduced significantly（P〈0.05）.Conclusion Intrauterine hypoxia reduces the numbers of neurons and the expression of nNOS in parietal cortex during postnatal development.Moreover,the ability to lean and memorize was reduced in adult mouse.