Figure 7. Systemic inhibition of aromatase after seizure onset suppresses electrographic seizures in gonadally intact rats.
(A) Schematic of experimental design. (B, C) Representative EEG (B) and normalized power spectrum (C) from one vehicle (Veh, top)- and one letrozole (Let, bottom)-treated rat. For EEG, the initial seizure in each animal is shown on the left. Teal bars above heatmaps indicate seizures detected by 5x baseline power in the β-low γ (10–50 Hz) range as the threshold. (D) Mean ± SEM normalized EEG amplitude plotted in 10 min bins for vehicle (blue, n=11)- and letrozole (orange, n=10)-treated rats. The seizure-related increase in EEG amplitude was suppressed by letrozole throughout 6 hrs of recording (p<0.05 post-hoc unpaired t-tests). (E) Mean ± SEM percent time in seizure using 5x baseline thresholds of EEG amplitude showing that the progressive increase in time in seizure evident in vehicle-treated rats was suppressed by letrozole (p<0.05 post-hoc unpaired t-tests). (F) Mean ± SEM normalized power spectrogram plotted in 1 Hz bins for δ-θ (1–10 Hz), β-low γ (10–50 Hz), and ripple (100–200 Hz) frequency ranges for vehicle (blue)- and letrozole (orange)-treated rats are shown for each 2 hr epoch. (H) Seizure-induced increases in power relative to baseline were lower in letrozole- than vehicle-treated rats in δ-θ and β-low γ ranges (ANCOVA, *p<0.05 and **p<0.01 between vehicle- and letrozole-treated rats, post-hoc unpaired t-tests). BL = baseline.
Figure 7—figure supplement 1. No difference in characteristics of 1st seizures in gonadally intact rats subsequently treated with vehicle or letrozole.
