The Establishment Of Mouse Alzheimer Disease Model And Galanin Expression Study

[Objective]To evaluate a mouse model of Alzheimer's disease (AD) with biochemical, histological, behaviour methods, and detect the expression of galanin and its receptors in such modlels. To understand the changes and actions of galanin and its receptors in process of AD.[Methods]The research work started from fifty BL/C57 mice, and mice were divided into model group and control group. D-galactose was injected into mice abdomical cavity for 90 days to form Alzheimer's disease model. While the control group were injected with 0.9% sodium chloride with the same amount.After 90 days, Y-maze test was used to test mice learning and memory abilities. The result of the first day showed learning abilities, and of 24 hours later was memory ability.Ten mice from each group were tested certain enzymes and substances in total brains, including AChE, ChAT, MDA, MAO, GSH-PX, SOD, Na~+-K~+-ATP. The detail processes were according to kit instructions.Five mice from each group were anaesthetized with pentobarbital sodium, then purfusesd with PFA(polyformalin), then the sensary-motor cortex in brain was fixed by glutaraldehyde for electron microscopy test.All the fixed brains were sectioned in the saggital plane, immunohistochemical protocols and fluorescent microscopes were both used to test galanin expression inhippocampus.Realtime-PCR technique was used to test the expression of galanin receptor 1 , 2, 3 in prefrontal lobe, midbrain periaqueductal gray[Results](1)Y-maze test explained that learning and memory abilities of model group was lower than control group.(2) Index of chemical substance showed activities about AChE, ChAT, GSH-PX, SOD, Na~+-K~+-ATP decreased in model group, and the content of MDA, MAO increased. (3) The photos of electron microscopy slides represented the sensory-motor cell's nucleus shank and their mitochondria crack in model group compared to the normal figure in control group.(4) Immunohistochemical protocols and fluorescent microscopes displayed thegalanin positive cells in hippocampus in model group was more than control group.(5) Realtime-PCR test showed that galanin receptor 1, 2, 3 expression in prefrontal lobe, midbrain periaqueductal gray in model group was more than control group.[Conclusions](1) The establishment of AD model was perfect for following research. (2)AChE, ChAT, GSH-PX, SOD, Na~+-K~+-ATPase activities decreased in AD,MDA, MAO increased, the free radicals content increased, which showed theproperty of AD.(3) Cells in AD had abnormal change: nucleus shank and mitochondria crack.(4) Galanin expressed highly in hippocamous in AD mice brain.(5) Galanin receptors expresseed highly in prefrontal lobe and midbrain periaqueductal gray...