Fig. 6

Modeling solute clearance. A Mean TSCs of outer and inner compartment for each group; AUCs represent CSF volumes. B, C Calculated CSF volumes of inner and outer compartment (Kruskal–Wallis test indicated an effect of experimental condition for both p < 0.001, post-hoc analysis was performed using Mann–Whitney-U test). D, E Exchange parameters \({k}_{1},{k}_{2}\) obtained by solving the differential Eq. (3), describing the exchange between outer and inner compartment (ANOVA test indicated an effect of experimental condition for both p = 0.018 for k₁ and p = 0.016 for k₂, post-hoc analysis was performed using Student’s t-test). F, G Exchanged volumes from outer to inner compartment (ANOVA test indicated no significant difference p = 0.10, post-hoc analysis was performed using Student’s t-test) or from inner to outer compartment (ANOVA test showed no significant effect of experimental condition p = 0.09, post-hoc analysis was performed using Student’s t-test) obtained by multiplying the exchange rates with the corresponding volume. H Net exchange ratio between the inner and outer volumes (ANOVA test showed an effect of experimental condition p = 0.007, post-hoc analysis was performed using Student’s t-test). I Schematic illustration of the two-compartment model for MED with almost similar exchange between inner and outer compartment. J Schematic illustration of the two-compartment model for ISO+MED with lower exchange ratio and higher permeation when compared to MED. Animal numbers used for all plots were ISO n = 8; MED n = 7; ISO+MED n = 8; ISO+AZE n = 10; MED+AZE n = 8; ISO+MED+AZE n = 8; a. u.: arbitrary units. * p < 0.05, ** p < 0.01, *** p < 0.001