Comparative power spectrum analysis of EEG activity in spontaneously hypertensive and Wistar rats in kainate model of temporal model of epilepsy.

Recently, we have reported that spontaneously hypertensive rats (SHRs) exhibit higher susceptibility than Wistar rats in kainate (KA) model of epilepsy. The aim of the present study is to compare the baseline of EEG signals in SHRs and Wistar rats using Discrete Fourier transform (DFT) during the three phases of KA model (acute, latent and chronic). The SHRs showed higher baseline relative power of delta waves in the left frontal cortex and lower gamma-HF waves in the left frontal and left/right parietal cortex, respectively, compared to Wistar rats. During the acute phase, both absolute and relative power of fast EEG bands (gamma-HF) was lower in the left/right frontal and the left/right parietal cortex in SHRs compared to Wistar rats. During the latent phase, no difference in the power of the investigated bands was detected between the two strains. During the chronic epileptic phase, the SHRs were characterized with higher power of HF oscillations than Wistar rats both in the frontal and parietal cortex without brain lateralization while theta, alpha and beta bands were with diminished power in the left parietal cortex of SHRs compared to normotensive Wistar rats. Taken together, the presented results suggest that the increased delta waves and lower gamma-HF waves in the frontal/parietal cortex are associated with a higher seizure susceptibility of SHRs compared to Wistar rats while fastest oscillations has a critical role in seizure generation and propagation of hypertensive rats.