Elevated neuronal excitability of CA1 pyramidal neurons in Kcnq2-null but not Kcnq3-null neurons. A, Voltage responses to various current injection steps (1 s) in pyramidal neurons from either control (n = 18), Kcnq2 cKO (n = 18), or Kcnq3 cKO (n = 18) mice. Membrane potential was kept at −60 mV by injecting a small DC current through the recording pipette. Representative traces showing the effects of deleting either Kcnq2 (red) or Kcnq3 (blue) on pyramidal neuron excitability. B, Summary graphs showing the effect of Kcnq2 or Kcnq3 deletion on CA1 pyramidal neuron AP number, initial firing frequency, and final firing frequency. Data shown are means ± SEM. Statistical significance was determined by two-way repeated-measures ANOVA (*p < 0.05).