Fig. 5

The mean values (± standard errors of the mean) of brain-derived neurotrophic factor (BDNF) protein concentration in the hippocampus were assessed for different methamphetamine (METH) groups. There was a significant difference in higher BDNF expression for the 5 mg/kg METH group than in the control and 1 mg/kg METH groups (P < 0. 01). BDNF expression was lower in the 10 mg/kg METH group than in the 5 mg/kg METH group, the 1 mg/kg METH group, and the control group (P < 0.001). There were no differences in BDNF expression between the 1 mg/kg METH group and the control group (^**P < 0.01; 5, and 10 mg/kg METH vs 1 mg/kg METH and control, ^!!!P < 0.001 10 mg/kg vs 5 mg/kg METH, n = 8)