A, Whole cell voltage clamp recordings from CA1 hippocampal pyramidal cells. Representative traces illustrating the increase in sIPSC amplitude and frequency following chronic treatment of mice with METH or its withdrawal (METH Wd) from 24 h to 6 weeks (6 wk). B, Mean ± SEM, sIPSC amplitudes (ANOVA, F(7,58)=71.7, P<0.0001; *P<0.05 vs. Con, METH WD-6 wk; †P<0.05 vs. all other groups.) and averaged sIPSC frequencies (ANOVA, F(7,58)=20.25, P<0.0001; *P<0.001 vs. Con, METH WD-6 wk; †P<0.05 vs. all other groups); n=5/group. C, Probability plot for the distribution of sIPSC amplitudes; left, Con, chronic METH and 24 h METH withdrawal; right, METH withdrawal, 2 – 6 wk.