Variability in mean midpoints of I_Na. (A) Reported mean midpoints of inactivation (μ_i, left) and activation (μ_a, right) for all experiments. Vertically, both sets of points are individually ordered from most to least negative membrane potential: correlations between an experiment’s μ_a and μ_i cannot be seen here and will be examined in Fig. 3. The SEM for each experiment is indicated by a thick black bar. A thinner grey bar shows the 5th-to-95th percentile range of a normal distribution with the reported mean and standard deviation: if the individual cell measurements in these studies were normally distributed, 90% of measurements would fall within this range. (B) A histogram view of the means. The y axis shows the percentage of reported means with each potential. (C) A histogram view of the standard deviations. A second x axis (top) shows the corresponding 5th-to-95th percentile ranges. (D) A histogram view of the number of cells measured per experiment.