Figure 1
From: Repeated episodes of postictal hypoxia are a mechanism for interictal cognitive impairments
Repeated seizures induce repeated postictal hypoxic (PIH) events. Rats were injected with either acetaminophen (250 mg/kg; 30 min prior to each kindling session) or nifedipine (15 mg/kg; immediately following seizure cessation) or their vehicles for 20 days. (a) Brain atlas plate depicting location of oxygen-sensing probe (left) and electrode stimulation site (right) in the CA3 area of the dorsal and ventral right hippocampus, respectively. (b) Representative EEG tracing depicting spike activity occurring during electrically induced seizures. LFP local field potential. (c,e,g,i) Hippocampal oxygen traces depicting changes in local pO2 before, during, and after electrically induced seizures. Different coloured traces indicate different kindling day. Horizontal dashed red line indicates the severe hypoxic threshold of 10 mmHg. Vertical dashed black line indicates seizure stimulation. Vertical light-yellow bar indicates when rats were unplugged from oxygen measurements to receive injections. Mean ± SEM (n = 7–8 each group). (d,f,h,j) Quantification of degree of severe hypoxia expressed as the area spent under the severe hypoxic threshold (10.0 mmHg) by time (min) for each experimental group (n = 7–8 each group). The Shapiro–Wilk test indicated a significant departure from normality (**p < 0.01) in the data distribution. Data are shown as median (95% CI), followed by non-parametric Friedman repeated measure ANOVA and Dunn’s post hoc test (*p < 0.05; **p < 0.01 versus Day 1 of kindling).
