Behavior and EEG recordings of the Kif4 ^Mut/Y mouse exhibit high susceptibility to seizure induction. (A–D) The results of the PTZ kindling test. The chart representing the seizure stage classification (A) of the individual scores from Kif4^WT/Y and Kif4^Mut/Y mice, before and after the PTZ injection. Statistical analysis results of the cumulative number of maximum (B) and all (C) seizure stage, and the ratio of the occurrence of stage 4 (D). Data are presented as mean ± SEM (n = 15 mouse pairs). ****P < 0.0001 (Student’s t tests). (E–H) The representative EEG recordings (E) and the results of the related time-frequency analysis using Morlet-Wavelet’s method (F). Red arrows and star marks indicate the timepoints of PTZ injections and the more energetic brain waves representing seizure onsets, respectively; M1, primary motor cortex; Hippo, hippocampus. (G) 45-second-long brain waves were picked up from hippocampal data in (E). The waveform the Kif4^Mut/Y mice exhibited was a spike-and-slow-wave pattern with a high electric current. (H) Spectrum analysis of post-PTZ injected individual mice using the FFT method. Note that the energy levels from 0.5 to 1.25 and 2 Hz in Kif4^Mut/Y mice were substantially higher than the control; PSD, power spectral density. Data are presented in (H) as mean ± SEM (n = 5 mouse pairs). *P < 0.05, ****P < 0.0001 (two-way ANOVA).