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Abstract: The autocrine motility factor receptor (AMFR) is a multifunctional protein involved in cellular adhesion, proliferation, motility and apoptosis. Our study showed that increased AMFR protein expression in the hippocampus of KM mice correlated with enhanced capacity for learning and memory following the shuttle-box test and was significantly elevated in the highest score group. Also, AMF and AMFR mRNA expression positively correlates with the mRNA expression of the synapse marker synaptophysin (Syp). Aging studies in the senescence-accelerated mouse strain (SAM) prone/8 (SAMP8), an animal model of Alzheimer''s disease (AD), revealed significantly decreased mRNA and protein expression of AMF and AMFR in the hippocampus. This is especially true for AMFR and AMF protein expression compared with age-matched SAM resistant/1 (SAMR1) mouse strain as the control. Additionally, the low mRNA expression of AMFR could be up-regulated by the four nootropic traditional Chinese medicinal prescriptions (TCMPs): Ba-Wei-Di-Huang decoction (BW), Huang-Lian-Jie-Du decoction (HL), Dang-Gui-Shao-Yao-San (DSS) and Tiao-Xin-Fang decoction (TXF). AMFR protein expression could be up-regulated by two TCMPs, Liu-Wei-Di-Huang decoction (LW) and BW. This indicated that AMFR is involved in the process of learning and memory in the central nervous system. These results may provide useful clues for understanding the etiology of AD. [Copyright &y& Elsevier]

Abstract: Vesicular glutamate transporters (VGLUTs), which include VGLUT1, VGLUT2 and VGLUT3, are responsible for the uploading of L-glutamate into synaptic vesicles. The expression pattern of VGLUTs determines the level of synaptic vesicle filling (i.e., glutamate quantal size) and directly influences glutamate receptors and glutamatergic synaptic transmission; thus, VGLUTs may play a key role in learning and memory in the central nervous system. To determine whether VGLUTs contribute to the degeneration or acquisition of learning and memory, we used an animal model for the age-related impairment of learning and memory, senescence-accelerated mouse/prone 8 (SAMP8). KM mice were divided into groups based on their learning and memory performance in a shuttle-box test. The expression of VGLUTs and synaptophysin (Syp) mRNA and protein in the cerebral cortex and hippocampus were investigated with real-time fluorescence quantitative PCR and western blot, respectively. Our results demonstrate that, in the cerebral cortex, protein expression of VGLUT1, VGLUT2, VGLUT3 and Syp was decreased in SAMP8 with age and increased in KM mice, which displayed an enhanced capacity for learning and memory. The protein expression of VGLUT2 and Syp was decreased in the hippocampus of SAMP8 with aging. The expression level of VGLUT1 and VGLUT2 proteins were highest in KM mouse group with a 76–100% avoidance score in the shuttle-box test. These data demonstrate that protein expression of VGLUT1, VGLUT2 and Syp decreases age-dependently in SAMP8 and increases in a learning- and memory-dependent manner in KM mice. Correlation analysis indicated the protein expression of VGLUT1, VGLUT2 and Syp has a positive correlation with the capacity of learning and memory. [Copyright &y& Elsevier]