Data Analysis

The acquired data were processed using the Clampfit 10 (Molecular Devices, Sunnyvale, CA, USA). Neurons with depolarized RMP (> −52 mV) were discarded without further analysis. Instantaneous current (I_Ins), steady-state current (I_ss), and current decay (tau) were calculated from the voltage-clamp recordings. Briefly, the I_Ins was located at the onset point of the 2-s hyperpolarizing step of each sweep and the I_ss was measured at the end of each 2-s hyperpolarizing step. The amplitude of Ih was measured by deducting I_Ins from I_ss at each sweep. Ih time constants were fitted with a standard exponential function of the equation: f(t)=∑i=1nAie−t/τi+C and expressed as the tau value in Clampfit. This is a basic function used to fit changes in current or voltage that are controlled by one or more first-order processes. The fit solves for the amplitude A, the time constant τ, and the constant y-offset C for each component i. The RMP, IR and AHP of pyramidal neurons and PV+ interneurons were measured from the current-clamp recordings. One-way ANOVA or two-way ANOVA analyses were performed on parameters by SPSS 23. For results with significant interaction effect in two-way ANOVA, simple effect test was conducted for further analysis. For results with insignificant interaction effect, Bonferroni’s post hoc test or Student t-test was further conducted as needed. All data are presented as mean ± standard error of the mean.