Abstract:Objective：To investigate the effects and the underlying mechanisms of Tenuigenin on Alzheimer’s disease by observing the effects of Tenuigenin(TEN) on expression of nicotinic acetylcholine receptor subunit alpha-4 (nAChRα4) and postsynaptic density 95(PSD-95) in Alzheimer’s disease model rat.Methods：32 male Wistar rats were divided randomly into four groups: control group，model group，12.5 mg·mL^-1dose TEN group and 37.5 mg·mL^-1dose TEN group. The rat model with Alzheimer’s disease was made by injecting ibotenic acid into Meynert basal nuclei of aging rat induced by D-gal.The expressions of nAChRα4 and PSD-95 in the hippocampus CA1 were measured by immunohistochemistry method.Results：Compared with the control group，the average gray-scale values of hippocampus CA1 nAChRα4 and PSD-95 in the model group were increased significantly and the average optical density was decreased obviously (P<0.01). Compared with the model group，the average gray-scale values in the hippocampus CA1 of 37.5 mg·mL^-1dose TEN group and 12.5 mg·mL^-1dose TEN group were obviously decreased and the average optical density was increased significantly (P<0.05). Meanwhile，the average gray-scale value within the hippocampus CA1 of 37.5 mg·mL^-1dose TEN group was significantly less than that in 12.5 mg·mL^-1dose TEN group，but more distinct than that on the average optical density aspect (P<0.01).Conclusion：TEN can dose-dependently increase the expression of CA1 area nAChRα4 and PSD-95 in Alzheimer’s disease model rats，which may partly explain the beneficial effects of TEN on cognitive function.

Key words:Tenuigenin,Alzheimer&,rsquo,s disease,hippocampus,nAChR&,alpha,4,PSD-95