Overexpression of γ-aminobutyric acid transporter subtype Ⅰ leads to cognitive deterioration in transgenic mice  

过量表达γ-氨基丁酸转运蛋白亚型Ⅰ导致转基因小鼠认知衰退(英文)

作　　者：马映华[1] 周筱刚[1] 段书惠 胡佳华 卢步峰 余莹 梅镇彤 费俭 郭礼和 

机构地区：[1]中国科学院上海生命科学研究院生物化学和细胞生物学研究所,上海中国200031 [2]中国科学院上海生理研究所,上海中国200031

出　　处：《Acta Pharmacologica Sinica》2001年第4期54-62,共9页中国药理学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China, № 39630140.

摘　　要：AIM: To explore the physiological role of y-aminobutyric acid transporter subtype Ⅰ(GAT1) in cognition. METHODS: Transgenic mice were produced by pronu-clei microinjection method. Integration of transgene was identified by Southern-blot and PCR analysis in various generations. Level of GAT1 mRNA in a variety of tissues was evaluated by semi-quantitative RT-PCR analysis. GAT1 protein was detected by immunofluorescence and histochemistry analysis. Associative learning capacity was analyzed by conditioned avoidance task. Memory retention was assessed by novel object recognition test. Morphology of synaptosomes was examined by electron microscope. RESULTS: Four independent founder mice bearing various copies of transgene were generated. GAT1 was evidently overexpressed at both mRNA and protein level in a variety of tissues from transgenic mice. In comparision with wild-type mice, transgenic mice exhibited significantly declined associative learning capacity (P < 0.01) and decreased memory retention ( P < 0.01 in 1-h-retention, and P < 0.05 in 1-d-retention). In addition , the amount of asymmetric synapses in the brain of transgenic mice was reduced approximately by 24 % , relative to wild-type mice. CONCLUSION: Overexpres-sion of GAT1 in mice results in cognitive deterioration, indicating that the alteration in the expression of γ-aminobutyric acid transporters is involved in the patho-physiological mechanism underlying some cognitive deficiencies .目的:研究γ-氨基丁酸转运蛋白亚型Ⅰ(GAT1)在认知中的生理功能。方法:原核显微注射法产生转基因小鼠。Southern-blot和PCR鉴定转基因的整合;半定量RT-PCR分析GAT1 mRNA水平;免疫荧光和免疫组化检测GAT1蛋白质表达。条件性回避行为分析联合型学习能力;新异物体识别行为分析记忆存储能力。电镜检查突触体形态。结果:获得4只含不同拷贝数转基因的建立者小鼠。GAT1在mRNA和蛋白质水平都呈过量表达。与野生型小鼠相比,转基因鼠联合型学习能力显著下降,视觉记忆显著减弱。另外,转基因鼠不对称突触数量减少约24％。结论:在小鼠中过量表达GAT1可导致认知衰退,表明γ-氨基丁酸转运蛋白表达的改变与某些类型认知缺陷的病理机制有关。

关 键 词：camer proteins gene expression COGNITION LEAMING memory synapses transgenic mice 

分 类 号：R749.1[医药卫生—神经病学与精神病学]