Figure 4.

Gephyrin G375D mutant fails to rescue increased seizure susceptibility in DG-specific gephyrin-cKO mice

(A) Schematic diagram of AAV vectors expressing Cre or ΔCre and WT gephyrin or its mutants (A91T and G375D) used for stereotactic injection into the DG of gephyrin floxed mice. Experimental scheme for seizure scoring and EEG recordings. The DG region of the hippocampus of ~6-week-old gephyrin floxed mice was bilaterally injected with AAVs-ΔCre or Cre, or co-injected with Cre- and gephyrin-WT–expressing AAVs (Cre + WT res.) or gephyrin-mutant–expressing AAVs (Cre + A91T res. or Cre + G375D res.). Mice were intraperitoneally administered KA 2 weeks after AAV injections, after which seizures were scored and EEGs were recorded.

(B) KA-induced seizures in mice injected with the indicated AAVs were scored every 3 min for a total of 120 min, as described in Supplemental Information. Data are presented as means ± SEMs (ΔCre, n = 7 mice; Cre, n = 7 mice; Cre + WT [res.], n = 7 mice; Cre + A91T [res.], n = 7 mice; and Cre + G375D [res.], n = 7 mice; ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001 vs. control; Kruskal-Wallis test followed by Dunn's post hoc test).

(C) Quantification of mean score values under each experimental condition. Data are presented as means ± SEMs (n = 7 mice/condition; ∗p < 0.05, ∗∗p < 0.01 vs. control; Kruskal-Wallis test followed by Dunn's post hoc test).

(D) Quantification of latency to the first seizure after KA administration under each condition. Data are presented as means ± SEMs (n = 7 mice/condition; ∗p < 0.05; Kruskal-Wallis test followed by Dunn's post hoc test).

(E) Quantification of time spent in seizure under each condition. Data are presented as means ± SEMs (n = 7 mice/condition).

(F) Representative EEG traces of ictal-like seizures recorded from the cortex under the indicated experimental conditions.

(G and H) Quantification of the number of ictal-like seizures (G) and total duration of ictal-like seizures (H) per hour under each condition. Data are presented as means ± SEMs (n = 8–11 mice/condition; ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001 vs. control; Kruskal-Wallis test followed by Dunn's post hoc test).

(I) Representative LFP traces of inter-ictal events recorded from the DG under the indicated experimental conditions.

(J) Quantification of the number of inter-ictal events under each condition. Data are presented as means ± SEMs (n = 5–6 mice/condition; ∗p < 0.05, ∗∗p < 0.01 vs. control; Kruskal-Wallis test followed by Dunn's post hoc test).