Drug doses
Diazepam was administered in a 2 mg kg-1 intravenous bolus dose, based on Riou et al., (1988b) and dose recommendations for human cases of overdose (Jones, 2015); and 10 mg kg-1in the study of high dose diazepam. The doses of clonazepam (1.1 mg kg-1) and Ro5-4864 (0.16 mg kg-1) were chosen to have the equivalent GABAergic and non-GABAergic activity, respectively, to 2 mg kg-1 of diazepam (Wang et al., 1984). Adrenaline was administered at 0.3 μg kg-1min-1, consistent with the recommended dose for the clinical treatment of overdose (Jones, 2015), and which produces a 50% increase in maximum rate of left ventricular pressure (LV +dP/dtmax) in anaesthetised rats (Latini et al., 1988).