酒精对幼鼠海马神经组织发育及Kainate受体的影响

The effects of ethanol on the hippocampal neural tissue development and kainite receptor expression in young mouse

目的探讨酒精对幼鼠神经组织发育及红藻氨酸(kainate,KA)受体表达的影响。方法从小鼠P7龄开始,用20%酒精皮下注射法建立胎儿酒精系列紊乱(fetal alcohol spectrum disorder,FASD)模型并以生理盐水注射的幼鼠为对照组(酒精实验组80只,对照组40只),两组各每天测量体重,并观察一般生物学特性,建模完成后进行Morrirs水迷宫行为学检测。另取P7小鼠30只(酒精实验组15只,对照组15只),皮下注射酒精和生理盐水24h后取脑组织进行FJB染色。免疫荧光法检测KA受体亚型KA1、KA2、Glu R-6及GFAP的表达情况。结果注射3周后,与对照组相比,实验组小鼠体重增长速度明显降低(对照组21.13g±1.72g,实验组13.96g±2.98g,P<0.05);Morrirs水迷宫实验发现,实验组较对照组逃避潜伏期时间明显延长(对照组21.05s±5.31s,实验组34.15s±3.26s,P<0.05),穿越平台次数也明显减少(对照组2.70次±1.25次,实验组0.93次±0.80次,F=2.505,P<0.05);GFAP荧光结果显示实验组小鼠从酒精注射7 d开始星形胶质细胞发育发生异常;FJB结果显示实验组皮质、海马、丘脑都有神经元细胞大量死亡;实验组小鼠P14龄Glu R-6和KA2亚型在海马CA区表达有上调。结论海马CA区KA受体Glu R-6和KA2亚型可能与酒精影响的幼鼠海马神经组织发育有关。

Objectives To investigate the effects of ethanol on neural development and kainate receptor expressionin young mice.MethodsFetal alcohol spectrum disorder model was established by administration of 20% ethanol solu-tion to 7-day-old Kunming mice and control animals received physiological saline（The number of treatment and controlwere 80 and 40, respectively）. Body weight and general biological features were observed every day. Morris water mazewas used to test learning and memory ability. Fluoro-Jade B was used to examine neural cells 24 hours after treatment inadditional thirty 7-day-old Kunming mice which were further divided into two groups： a treatment group receiving 20%ethanol solution（n= 15） and a control group receiving physiological saline（n=15）. The development of neural cells andexpression levels of kainite receptors were examined by using immunofluorescence staining.ResultsThe body weightwas significantly lighter in treatment group than in control group（control：21.13 ± 1.72 g,treatment：13.96 ± 2.98 g,P〈0.05）. Morris test showed that model group had longer latency than control group to find hidden platform（control：21.05±5.31 s,treatment：34.15±3.26 s,P〈0.05）. Spatial probe test revealed that the number of passing through the platform weresignificantly smaller in model group than in control group（control：2.70±1.25 times,treatment：0.93±0.80 times,P〈0.05）. Astrocyte development anomaly was evident after ethanol treatment for 7 days. The expression levels of kainite re-ceptor Glu R-6 and KA2 were up-regulated in the CA region of the hippocampus after ethanol treatment for 7 days.ConclusionKainite receptor Glu R-6 and KA2 in CA region of the hippocampus may contribute to ethanol-induced hippo-campal neural development anomaly.