Aim To explore the molecular mechanism of interrelationship between thioridazine-induced learning and memory decline and the production of ?-amyloid (A?) in the rat brain. Methods Male Sprague-Dawley rats were injected intraperitoneally with thioridazine of 10 mg?kg-1?d-1 for 2 weeks in order to suppress cognition by inhibition of dopamine, acetylcholine and 5-hydroxytryptamine receptors. Morris water maze was used to measure spatial learning and memory performance. The A? content of brain was measured by radioimmunoassay. Immunohistochemistry was employed to determine ?-amyloid precursor protein (APP) level. The mRNA levels of APP,?-secretase and ?-secretase in brain were detected by RT-PCR. Results Thioridazine treatment to rats resulted in spatial learning and memory impairment shown by longer escape latency. Total A? was significantly increased by 1.3 times in thioridazine-treated rats. APP-immunoreactivities in cortex and hippocampus of thioridazine-treated rats were more pronounced than those of control rats. Levels of APP751 plus APP770 mRNA,?-secretase mRNA in brain increased nearly 2.5 and 2.6 folds respectively in thioridazine treated-rats, but no differences in mRNA levels of APP695 and ?-secretase were found between thioridazine-treated and control rats. Conclusion The thioridazine-induced cognitive decline is related to the increase of A? caused by elevation of APP751,APP770 and ?-secretase expression.

Objective To investigate the effect of very-long-chain saturated fatty acids on Tau protein phosphorylation and membrane fluidity in human neuroblastoma SH-SY5Y cells,and to explore its role in the pathogenesis of Alzheimer's disease(AD).Methods Human neuroblastoma SH-SY5Y cells in logarithmic growth phase were randomly divided into control group,C22∶0 group,and C24:0 group.Cells in the control group were routinely cultured,while cells in the C22:0 and C24:0 groups were treated with culture medium containing 10 μmol·L-1very-long-chain saturated fatty acids C22:0 and C24:0,respectively.After 24 hours of incubation,cells were collected.The expression levels of total Tau protein,phosphorylated Tau protein at serine 396 site(p-Tau-ser396),glycogen synthase kinase 3β(GSK-3β),and phosphorylated GSK-3 β protein at serine 9 site(p-GSK-3β-Ser9)in cells of each group were detected by using Western blot.The malondialdehyde(MDA)level in cells of each group was determined by using the thiobarbituric acid method.The fluorescence recovery rate and diffusion coefficient of cell membranes were measured by using fluorescence recovery after photobleaching technique,and the fluidity of cell membranes was evaluated.Results The total Tau protein level in SH-SY5Y cells showed no statistically significant difference among the three groups(F=1.807,P＞0.05).However,there was a statistically significant difference in the level of p-Tau-ser396 in SH-SY5Y cells among the three groups(F=18.397,P＜0.05).Specifically,the level of p-Tau-ser396 in SH-SY5Y cells in the C22:0 and C24:0 groups was significantly higher than that in the control group(P＜0.05),and the level of p-Tau-ser396 in SH-SY5Y cells in the C24:0 group was significantly higher than that in the C22:0 group(P＜0.05).There was no statistically significant difference in the GSK-3 β protein level in SH-SY5Y cells among the three groups(F=0.351,P＞0.05).However,there was a statistically significant difference in the level of p-GSK-3β-Ser9 in SH-SY5Y cells among the three groups(F=13.330,P＜0.05).Specifically,the level of p-GSK-3β-ser9 in SH-SY5Y cells in the C22:0 and C24:0 groups was significantly lower than that in the control group(P＜0.05),and there was no statistically significant difference in the level of p-GSK-3β-ser9 in SH-SY5Y cells between the C22:0 group and C24:0 group(P＞0.05).The MDA level in SH-SY5Y cells in the C24:0 group was significantly higher than that in the control group and C22:0 group(P＜0.05);there was no statistically significant difference in the MDA level in SH-SY5Y cells between the control group and C22:0 group(P＞0.05).The fluorescence recovery rate and diffusion coefficient of SH-SY5Y cells in the C22:0 and C24:0 groups showed a decreasing trend compared to the control group,but there was no statistically significant difference in the fluorescence recovery rate and diffusion coefficient of SH-SY5Y cells among the three groups(F=3.891,3.649,P＞0.05).Conclusion Very-long-chain saturated fatty acids C22:0 and C24:0 can promote hyperphosphorylation of Tau protein,induce cellular oxidative damage,and tend to reduce the fluidity cell membranes.Very-long-chain saturated fatty acids may be one of the factors that cause the onset of AD.

ObjectiveOptimize the latex perfusion technique and apply it to the construction of a murine craniofacial venous vascular model.Methods A total of nine 8-week-old male C57BL/6 mice weighing (25.0±1.3) g were randomly divided into three groups: 60% latex physiological saline group, 60% latex heparin group, and 30% latex heparin group. After completion of the perfusion, the specimens were immersed in 4 °C formalin fixative for 24 h, followed by dissection, observation, and measurement of the extracranial blood vessel diameters. Results After 200 μL latex perfusion solution was injected into the external jugular vein, the supraorbital vein, infraorbital vein, temporal vein, retrofacial vein, masseter vein and external jugular vein were perfused in each group.After comparing the perfusion degree of the distal branches of blood vessels, sublingual vein and tip venule, it was found that the 30% latex heparin group had the best perfusion effect, followed by the 60% latex heparin group, and the 60% latex saline group had the worst perfusion effect.ConclusionThe optimized latex perfusion technique can effectively infuse the veins in the head and face of mice, and this technique can provide a good reference for the study of the direction and morphology of facial veins in mice.