Adrenergic-deficient mice exhibit volatile anesthetic hypersensitivity relative to sibling controls with normal levels of norepinephrine/epinephrine. Symbols respectively depict the fraction of Dbh+/− (n=10, triangles) and Dbh−/− (n=12, circles) mice that exhibit a loss of righting reflex (LORR) at each specified anesthetic dose for (A) isoflurane, (C) sevoflurane, and (E) halothane. Solid lines denote the best-fit curves with dashed lines showing 95% confidence interval bracketing the best-fit curves. Bars represent mean ± SEM time lapsed from the termination of anesthetic exposure (shown in A, C, E) until the return of righting reflex (RORR) for Dbh−/− (black) and Dbh+/− (colored) mice for (B) isoflurane, (D) sevoflurane, and (F) halothane. Effects of genotype are significant F1,236=46.7, p < 0.0001. Atm: atmosphere; Dbh: dopamine β-hydroxylase.