Research Paper Volume 12, Issue 18 pp 17845—17862

Figure 6. Mice treated with metformin by tail vein injection showed better performance in the Morris water maze test. (A) Mice treated with metformin (n = 12) for 10 months showed a considerable disability rate compared with the control group (n = 12). (B) Twenty-month-old mice treated with metformin by tail vein injection (n = 4) showed a better performance in escape latency than mice treated by oral administration (n = 6). (C) Probe tests conducted at 24 h after the acquisition phase indicated that the first time-to-platform of 20-month-old mice treated with metformin by tail vein injection was shorter than in mice treated by oral administration. (D) No difference in swim speed was observed between control and metformin-treated groups (tail vein injection or oral administration). Ctrl: Control; Met: Metformin. The overall significance between two groups was determined by Student’s t-test, among three group was determined by one-way ANOVA. * p < 0.05, ** p < 0.01, *** p < 0.001, ns, not significant.