不同孕期被动吸烟对仔鼠学习记忆行为及海马神经元凋亡的影响

Influence of passive smoking during different stage of pregnancy on study and memory behavior and neuron apoptosis in hippocampus of offspring of rats

目的:探讨不同孕期被动吸烟对仔鼠空间学习记忆力及海马神经元凋亡的影响。方法:分别在孕早、中、晚期予SD母鼠以被动吸烟,仔鼠出生后1月龄时,用Morris水迷宫检测其空间相关性学习记忆能力,用TUNEL染色法检测海马区神经元的凋亡情况。结果:水迷宫试验中实验组仔鼠寻找站台的潜伏期长于对照组,除中期组雌鼠实验组与对照组无显著差异外,其余各实验组和对照组比较均有显著差异(P<0.05);定位航行试验中,实验各组仔鼠通过站台区的次数均少于对照组。除中期组雌鼠和晚期组雄鼠的实验组和对照组无显著差异外,其余实验各组和对照组比较均有显著差异(P<0.05)。实验组仔鼠海马区神经元凋亡指数明显高于对照组(P<0.05),且以孕早期被动吸烟的凋亡指数最高(P<0.05)。结论:不同孕期被动吸烟对仔鼠的学习记忆能力和神经发育造成不良影响。海马区神经元凋亡增加可能参与了孕期被动吸烟造成仔鼠学习记忆力减退的机制。

Objective：To investigate the effect of passive smoking during different stage of pregnancy on study and memory behavior and neuron apoptosis in hippocampus of offspring. Method：Pregnant rats were exposed to smoking during different stage （first trimester, second trimester or third trimester, respectively）. When the offspring were 1 month old, their study and memory ability were examined by Morris water maze, and the neuron apoptosis in hippocampus of those offspring were examined by terminal deoxynucleotidyl transferase mediated nick end labeling ＇（ TUNEL）. Results：During the Morris water maze test,the offspring of those smoking-exposed rats had worse achievements ： they spent more time to find the platform than those of the control group, and less occasionally did they got through the area in which the platform was placed. The apoptosis indexes of the hippocampus neuron of smoking-exposed offspring were higher than those of the control（P〈0.05 ）. And the apoptosis index of the first trimester was the highest（P〈0. 05）. Conclusion： Passive smoking during pregnancy may cause decrease of study and memory ability of their offspring. Passive smoking may also cause underdevelopment of brain neuron of their offspring. Neuron apoptosis in hippocampus may be related to the decrease of study and memory ability.