Figure 1. Halothane-induced locomotion defects. For the loopy/sluggish uncoordinated movement defect induced by halothane, 10 young adult animals per data point were scored by an observer blinded to drug concentration. For immobilization, 30 to 50 animals per data point were scored for lack of spontaneous movement of any type during a 5-s period. Median effective concentrations and standard errors are estimated by logistic regression.