Fig. 5. Box plots of the median number of the cerebrospinal fluid (CSF) samples that had measurable concentrations of baclofen at each sampling site. The total number of samples collected at each sampling site was 26 per animal. Box  indicates interquartile range, line across box  indicates median, whiskers  indicate range excluding outliers, and open circles  indicate outliers. * Indicates a statistically significant difference (P < 0.05, Mann–Whitney U test) between the horizontal and vertical groups within sampling sites. No between-sampling site comparisons were made.