Figure 2. Reduced seizure threshold in excitatory neuron-specific or adult conditional Celf4^null mice.

Generalized seizure threshold was measured by ECT test in conditional knockout mice. The average seizure threshold in milliamps (mA) ± SEM for individual mice in each group is shown; threshold values for female (left) and male (right) mice are shown separately because female mice typically have a lower standard threshold (Frankel et al. 2001). The number of mice in each test group is indicated in parentheses beside the group description on the x-axis. Experimental mice were cre⁺ and either Celf4^flox/flox homozygotes or Celf4^flox/+ heterozygotes. Experimental ER-Cre mice and littermate controls were treated with tamoxifen (tam) by oral gavage at seven weeks of age for five sequential days and tested twelve days after completion of treatment. Control mice for each experiment were either Celf4^flox/flox homozygotes or Celf4^flox/+ heterozygotes that were cre⁻, Celf4^+/+ with or without cre expression, or a combination of these groups (see Supplemental Table 1). All mice were on a C57BL/6J strain background, except for the Viaat-Cre mice which were tested on the (C57BL/6J × FVB/NJ)F₁ hybrid background, which has a significantly lower seizure threshold than C57BL/6J itself as seen in the figure. A regression fit model was used to assess statistical significance incorporating both sex and treatment (experimental versus control) as independent covariates. The reduced ECTs of the germline, the adult, and the excitatory neuron-specific deletions were statistically significant. P-values were: germline (EIIa-Cre, p < 0.0001); adult (ER-Cre, p < 0.0001); excitatory (Camk2a-Cre, p < 0.01; Emx1-Cre, p < 0.001); inhibitory (Pvalb-Cre, p > 0.5; Viaat-Cre, p < 0.01).