(A) Example of raw electroencephalogram traces at 0.3% isoflurane during an emergence protocol in the parietal association cortex recording site, which illustrates the predominance of slow-frequency, high amplitude waves in Dahl salt sensitive compared to Brown Norway rats. (B) Examples of traces used to determine single (a) and double (b) τ values. Electroencephalogram frequency was plotted as a function of electroencephalogram power on a log-log scale and used to generate the exponential rates (τ) of shift in the total power of frequency changes between 1 and 59 Hz. As described in the text, data were best fit to a single or double exponential expression. A more negative value of τ indicated a shift toward lower frequencies while a less negative value of τ indicated a shift toward higher frequencies. (Note: scales truncated to region of interest from 0 to 60 Hz).