Figure 3. Concentration-response relationships of anesthetic-induced depression of mean spike rates for (A) propofol, (B) ketamine, (C) pentobarbital, and (D) ethanol. The data points represent mean values +/- SE. Concentrations are also given as multiples of the in vivo median effective concentrations (MEC50) at the top of each graph. The effects of the tested anesthetics were calculated by comparing action potential discharge rates before and during the treatment. For each tested concentration, the mean value was calculated from 5–12 cells. The curves were fitted with Hill equations to the data points. The median effective concentrations and the Hill coefficients derived from the fits are summarized in Table 2.
