低浓度酒精对成年大鼠空间位置的记忆及海马CA1区BDNF表达的影响

目的探讨低浓度酒精摄取对成年大鼠空间位置记忆的影响,并通过免疫组织化学方法检测低浓度酒精摄取后海马CA1区脑源性神经营养因子(BDNF)的表达。方法成年雄性SD大鼠给予连续3d Morris水迷宫训练,然后动物随机分为实验组和对照组。实验组动物给予5%(V/V)酒精为唯一饮料喂养,对照组动物以自来水代替酒精。在给与酒精喂养后的3,7,14,21,30d行Morris水迷宫行为观察。动物在水迷宫行为学观察后,取脑、冰冻切片,用ABC法行BDNF免疫组织化学反应,用Motic 3．2图像分析系统测定免疫反应阳性产物的平均灰度值。结果给予低浓度酒精喂养3d与7d后,动物找到平台的潜伏期[分别为(8．93±1．38)s,(9．66±1．04)s]与对照组[分别为(8．24±2．94)s,(10．07±O．71)s](P＞0．05),酒精喂养14,21,30d后,动物找到平台的潜伏期[分别为(9．19±1．81)s,(10．45±0．97)s,(12．37±1．81)s]明显短于对照组[分别为(17．14±3．66)s,(18．83±1．25)、s,(21．41±2．73)s],差异有显著性(P＜0．05)。BDNF的免疫组化反应显示低浓度酒精喂养3d时BDNF在海马CA1区的表达平均灰度值(145．3±14)与对照组(143．8±12)相比差异无显著性(P＞0．05)；而低浓度酒精喂养7d、14d与21d时,海马CA1区BDNF的表达平均灰度值(分别为125．6±17,127．4±15,130．7±14)明显低于对照组(分别为147．5±13,142．7±10,145．8±16)(平均灰度值与阳性产物的多少成反比)(P＜0．05)；酒精连续喂养30d后,海马CA1区BDNF的表达平均灰度值(146．2±11)接近于对照组(144．5±14),差异无显著性(P＞0．05)。结论短期内低浓度酒精摄取有助于成年大鼠空间位置记忆的保持,其机制可能与低浓度酒精摄取上调BDNF在海马CA1区的表达有关。

Effects of low density ethanol consumption on the spatial memory and the expression of BDNF in the hippocampal CA1 region of adult rat

Objective To explore the effects of low density ethanol consumption on the spatial memory and the expression of BDNF in the hippocampal CA1 region of adult rat.Methods Adult male rats were trained three days in Morris water maze before they divided into experimental group and control group.Experimental group rats were used 5% ethanol as absolute beverage to breed for 3,7,14,21,30 day;control group rats were used tap water instead of ethanol.Spatial memory was detected by Mort'is water maze and BDNF expression was detected by immunohistochemisty in CA1 region of hippocampus.Results The escape latencies of rat were decreased obvi- ously after 5% ethanol treated for 14,21 and 30 day and the expression of BDNF in the hippocampal CA1 region was increased obviously after 5% ethanol treated for 7,14,and 21 day compared with control group.Conclusion Short-term low density ethanol consumption may promote the maintenance of adult rat spatial memory and the ex- pression of BDNF in CA1 region of hippocampus.