Table 11-Suppression of Apomorphine-Induced Pecking Syndrome by Chlorpromazine (CPZ) and Methdilazine (MDZ) Assayed by Two Methods Method Statistic Visual Instrument IDSO (CPZ). 2.05 (1.10-3.80) 1.65 (0.90-2.95) 29.8 (24.0-37.0) 27.1 (20.9-34.6) Slope (CPZ)b 92.9 f . 29.1 82.6 f 30.7 rD50(MDZ) 84.9 =t 67.5 Slope (MDZ) 71.6 =t 47.4 Common slope 90.11 78.43 Relative potencyC 0.072 (0.046-0.100) 0.063 (0.043-0.96) @ Median inhibiting dose (95% confidence limits): in unit of micromoles of base per kilogram body weight. * Slope of the dose-response line f 95 % confidence limits; in units of percent/log dose. c Potency of MDZ (95 % confidence limits) relative to CPZ. (CPZ) + (MDZ) activity obviates deriving CPR values by curve plotting and area computing manipulations. And, finally, the comparatively unsophisticated device can be fabricated with standard and readily available components. It seems clear from the results summarized in Tables and that the instrument monitor provides data as accurate and as reliable as those provided by the more tedious visual method. The results of the inhibitor potency assay, particularly, demonstrate the utility and applicability of the instrument method for such experiments.