How significant is the difference between drug doses influencing the threshold for electroconvulsions?

In this study, three computational methods (log-probit, one-way analysis of variance and linear regression analysis) were applied to statistically determine and compare a minimal dose of the antiepileptic drug--levetiracetam (LEV), which significantly increased the threshold for maximal electroconvulsions in mice. Results analyzed with log-probit method revealed that such a dose for LEV was 50 mg/kg. In contrast, one-way ANOVA indicated that the minimal dose of LEV, fulfilling the criterion of the significant increment in the threshold for electroconvulsions, was 100 mg/kg. Moreover, linear regression analysis allowed for the determination of threshold increasing doses by 20% (TID20) and 50% (TID50) for LEV, which amounted to 44 mg/kg and 150 mg/kg. This comparative study demonstrated distinct differences between the electroconvulsive threshold-influencing doses of LEV calculated with these three methods, and only statistical evaluation of data using one-way ANOVA provided the most adequate determination of statistical significance. The application of log-probit method and linear regression analysis in the search for significant drug-dose effects should be substantially restricted to specific experimental conditions.