GFAP and Alzheimer disease: To investigate the effect of astragaloside IV (ASI) on the proliferation and differentiation of the engrafted neural stem cells (NSCs), we cultured NSCs from the hippocampus of E14 rat embryos, treated the cells with ASI, and then transplanted the cells into the hippocampus of rat AD models. In vitro experimentation showed that 10−5 M ASI induced NSCs to differentiate into β-tubulin III+ and GFAP+ cells.