Objective Through the observation on the distribution of hyperphosphorylated Tau,to investigate the connection between hyperphosphorylated Tau and learning, memory tasks. Furthermore, the treatment of App17 on brain tissues of diabetic mice. Methods Diabetic model mouse was produced in the use of streptozotion and App17 peptide as a curative was injected subcutaneously. Four weeks later, removed the brains. Immunohistochemical stainning was done with AT\|8, Tau\|1, again with Tau\|1 antibody after dephosphorylation. Results In the brains of diabetic mice positive AT\|8 reacting neurons were widely distribution in retrosplenial granular cortex, hippocampas, thalamus et al, the cytoplasm was darkly stained, while in normal mice and App17 peptide\|treated diabetic mice positive cells were localized in retrosplenial granular cortex, however, in hippocampas and RSG area, the cytoplasm were poorly stained. Conclusion Hyperphosphorylated Tau is widely expressed in brains of diabetic mice. App17 peptide can improve the hyperphosphorylated Tau in brains of diabetic mice, therefore, it may improve learning ability and memory.\;

Objective To investigate the effect of a peptide,APP17,on regulating the expression of insulin receptor substrate\|1(IRS\|1) and insulin\|like growth factor (IGF\|1R) in neurons of the hippocampus from diabetic mouse. Methods Diabetic mouse models were established by injection of streptozotion.In experimental group,these models were injected with APP17 peptide subcutaneously and their brain sections were taken after 4 weeks of survival. The immunohistochemical stainning of these sections were then performed with IRS\|1 and IGF\|1R antibody.With regard to control groups,the mouse models were only injected saline and gone through the same procedure of immunohistochemistry together with normal mice. Results IRS\|1 and IGF\|1R positive neurons were widely distributed in the hippocampus of the diabetic mice,and the cytoplasm was darkly stained.In the contrast,positive cells in the hippocampus were lightly stained in those normal mice and the APP17 peptide\|treated diabetic mice. Conclusion The expression of IRS\|1 and IGF\|1R could increase in the hippocampus of dabetic mice.The APP17 can regulate the distribution of IRS\|1 and IGF\|1R in the brain of diabetic mice and return them to normal situation.