Fig. 3.

Ovariectomized LDLR ^−/− mice showed severe neurotransmitter abnormalities and hippocampal damage. C57BL/6 and LDLR^−/− mice were fed a ND or HFD for 90 days. Bilateral ovariectomy was performed in LDLR^−/− mice fed a HFD to simulate a postmenopausal stage. A The hippocampi of mice were obtained after 90 days of administration, and the levels of Ach, DA and NE in hippocampal homogenates were detected using ELISA kits. B The activities of AChT and AchE in hippocampal homogenates of mice were detected using biochemical kits after 90 days of administration. C The hippocampi of mice were obtained after 90 days of administration. The changes in Nissl bodies in hippocampal tissues were detected by Nissl staining. The representative images show the changes in Nissl bodies in the whole hippocampus, DG, CA1 and CA3 areas, and the magnification and scale bar are marked in the representative images. The quantity of Nissl bodies in hippocampal tissue and the DG region was quantified. D The expression of PSD-95 and Tau in the hippocampal tissues of mice was detected by immunofluorescence staining after 90 days of administration. The magnification and scale bar are marked in the representative images. The expression levels of PSD-95 and Tau in the hippocampus were quantified by the mean optical density. E The cell apoptosis in the hippocampal tissues of mice was detected by tunel staining after 90 days of administration. The number of apoptotic cells in each view was counted. A–D, n = 5. E, n = 4. In the indicated comparison, *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001