Figure 3

Fast oxygen dynamics are associated with absence seizures. (a) Representative neocortical pO₂ recordings from a GAERS rat (orange) and NEC rat (blue). Inset shows 1 minute of data revealing fast oxygen dynamics overlaying slower oscillations. (b) Power spectral density analysis of GAERS (n = 5) and NEC (n = 3) oxygen recordings plotted on a logarithmic dB scale. Greater power in GAERs rats is observed between 0.08–0.1 Hz (t(6) = 3.19, *p < 0.05). (c) Analysis from (b) applied to hippocampal data (GAERS, n = 4; NEC, n = 3) revealing no significant change. (d) Representative filtered oxygen data (high-pass filter at 0.08 Hz) from Panel a. Inset shows 1 minute of data displaying enhanced amplitude at high frequency. (e,f) Standard deviation (SD) of filtered oxygen data for neocortical and hippocampal recordings, respectively. GAERS rats have significantly higher neocortical SD than NEC controls (t(6) = 2.55, *p < 0.05). A line drawn at an SD of 0.095 mmHg is able to separate epileptic rats from controls and distinguish non-epileptic brain regions.