Fig. 5.
Global shifts in electroencephalogram activity corresponded to behavioral findings. Data illustrated are mean ± SEM τ as a function of inhaled isoflurane level for Dahl Salt Sensitive (SS, dashed line) and Brown Norway (BN, solid line). (A) During induction, amplitudes of τ were larger, indicative of early excitation in BN compared to SS between 0.3 and 0.6% inhaled isoflurane. Therefore, in contrast to other all other isoflurane dose-response patterns, averaged τ measurements did not follow a linear trend in BN and the slope of the regression line was not statistically different from zero. (B) During induction, averaged τ measurements in the primary motor cortex (M1) of SS rats were lower compared to BN below 0.3% inhaled isoflurane, and low-frequency synchrony persisted longer in SS compared to BN rats. (C) During emergence, averaged τ measurements in the parietal association cortex (PtA) of SS rats were lower compared to BN below 0.8% inhaled isoflurane (the dose at which one-half of BN rats recovered the righting reflex) and low-frequency synchrony persisted longer in SS compared to BN rats. (D) Similar to PtA, low-frequency synchrony persisted longer in SS compared to BN rats at M1 recording sites, but, unlike PtA, average amplitudes of τ were not different at individual inhaled isoflurane concentrations. * P ≤ 0.05 for the slope of the linear fit in SS versus BN; † P ≤ 0.05 for the amplitude of τ in SS versus BN, § slope not different from zero at P ≤ 0.05, n = 11 for SS and 12 for BN.