The levels of Alzheimer's disease (AD)-related genes, including β-amyloid precursor protein(APP), presenilin-1 (PS-1), PS-2, apoE, tau, c-fos, neural cell adhesion molecular 180 (NCAM-180), TGF-β1, IL-1α/β, IL-6, TNF-α/β, α-2-Macroglobulin (α2M), class II major histocompatibility antigen Ia (MHCII Ia), bcl-2α, glucocorticoid receptor-α (GRα) and mineralocorticoid receptor (MR) mRNAs were determined by reverse transcription polymerase chain reaction (RT-PCR) in the hippocampus and cerebral cortex of senescence accelerated mouse (SAM). The levels of TGF-β1, IL-1α, TNF-β, c-fos, NCAM-180, PS-1 and APP mRNAs were normally expressed in SAMP8 compared with age-matched other subline that is resistant (SAMR1). The levels of apoE, GRα and MR mRNAs in the hippocampus of SAMP8, especially GRα, were evidently lower than those in the hippocampus of SAMR1. While bcl-2α, PS-2 and tau mRNA levels of SAMP8 were significantly higher than those of SAMR1. Inflammatory cytokines (IL-1β, IL-6, TNF-α), α2M and MHCII Ia antigen mRNAs were not detected in the brain of SAM. The differences of gene expression in the cerebral cortex were less evident than in the hippocampus. The results indicated that some genes abnormally expressed in the AD brain were also found in the brain of SAMP8, which may contribute to its age-related deterioration of learning and memory. Our results also suggested that functional and pathological changes which occurred in the brain of SAMP8 possessed some different aspects in comparison with the AD in consideration of the differences in gene expression.