Figure 3. Metformin rejuvenation of neurogenic potential in aged mice. (A) The subventricular zone (SVZ) of old mice treated with metformin (n ≥ 3) immunostained with the neural stem cell marker, Sox2, and newborn neuronal marker, DCX. Right: Quantification of (B) Sox2+ cells and (C) DCX+ cells. (D) SVZ of old mice immunostained with the neuronal cell marker, NeuN, and cell proliferation marker, BrdU. Right: Quantification of (E) BrdU+ /NeuN+ cells to quantify newborn neurons. (F) Representative fields of GFAP and Tuj1 immunofluorescence staining of cultured neural stem cells treated with metformin after 7 days of spontaneous differentiation. Right: Statistical analysis of percentages of (G) GFAP+ cells and (H) Tuj1+ cells. Scale bar = 100 μm. Ctrl: Control; Met: Metformin. The overall significance between two groups was determined by Student’s t-test. * p < 0.05, ** p < 0.01, *** p < 0.001, ns, not significant.