Sgk, A Primary Glucocorticoid-Induced Gene, Facilitates Memory Consolidation of Spatial Learning in Rats

• Main Authors: Kuen-Jer Tsai, 蔡坤哲
• Other Authors: Eminy Hsiao-Yuan Lee
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/12651360432766087094

博士 === 國防醫學院 === 生命科學研究所 === 90 === By using differential display PCR, we have identified 98 cDNA fragments from the rat dorsal hippocampus that are differentially expressed between the fast learners and slow learners in the Morris water maze learning task. One of these cDNA fragments encodes the rat serum- and glucocorticoid-inducible kinase (sgk) gene. Northern blot analysis revealed that the sgk mRNA level was approximately four-fold higher in the hippocampus of fast learners than slow learners. In situ hybridization results indicated that sgk mRNA level was markedly increased in CA1, CA3 and dentate gyrus of hippocampus in fast learners. Transient transfection of the sgk mutant DNA to the CA1 area significantly impaired, while transfection of the sgk wild-type DNA markedly facilitated water maze performance in rats. These results provide the first and direct evidence that enhanced sgk expression facilitates memory consolidation of spatial learning in rats. These results also elucidate the molecular mechanism of glucocorticoid-induced memory facilitation in mammals.