Fig. 4

Nissl staining of hippocampal three subregions (CA1, CA3, and DG) (magnifification × 400; scale bars = 100 μm). Stained Nissl bodies can be observed in normal hippocampus neurons (yellow arrow). The degree and number of morphological changes in hippocampus neurons in each group showed significant differences (orange arrow). The neurons in the Aβ group had obvious necrosis, mainly in the form of atrophy and irregularity of neurons. The nuclei showed dark deposits. Dehydration and vacuolar structure formation occurred in the cytoplasm. The neurons in the Aβ + AST + NAM group exhibited morphological changes similar to those in the Aβ group. In the Aβ + AST group, the morphological changes in the neurons are better than that in the Aβ and Aβ + AST + NAM groups (n = 4/group)