Fig. 6. Power-density spectrum of the local field potential; sample sizes are n = 9 for the wild type and n = 8 for β³(N265M) mutant. (  A ) Power spectra for wild type (open circle) and β³(N265M) mutant (open triangle) mouse preparations under control conditions. The averaged power densities with a peak close to 6 Hz were not significantly different between both types of preparation (  P > 0.05). (  B ) The effect of 0.2 μm etomidate (solid circle) compared with control (open circle) in the wild type: etomidate enhances power between 3 and 8 Hz; however, statistical significance is not reached (  P > 0.05). Note the large standard errors of the mean compared with the mutant preparation. (  C ) The effect of etomidate (solid triangle) compared with control (open triangle) in the β³(N265M) mutant: the anesthetic decreases power between 3 and 8 Hz (  P < 0.05). (  D ) The difference spectra are obtained by subtracting control from drug condition for both wild type and mutant. Etomidate exhibits opposing actions on theta range oscillations in wild type (solid circle) and β³(N265M) mutant (solid triangles), most prominent between 3 and 8 Hz. Note the different scale bar compared with (  A )–(  C ).