Fig. 4

GLP-1R inhibition reduces choroid plexus transport activity. A Schematic representation of the ⁸⁶Rb⁺ isotope flux assays with uptake on the left panel and efflux on the right panel. B⁸⁶Rb⁺ influx into acutely excised choroid plexus in the presence and absence of ouabain (Ouab), following pretreatment with Ex9-39, Ex4, or vehicle, n = 6 of each. C The ouabain-sensitive fraction, representing the Na⁺/K⁺-ATPase-mediated ⁸⁶Rb⁺ influx in each choroid plexus, in control conditions and in the presence of Ex9-39 and Ex4, n = 6. D Efflux of ⁸⁶Rb⁺ from choroid plexus as a function of time in control settings and following pretreatment with Ex9-39 or Ex4 in the absence or presence of bumetanide (Bum), n = 6 of each. The y-axis is the natural logarithm of the remaining ⁸⁶Rb⁺ in the choroid plexus at time t (A_t), divided by the amount at time 0 (A₀). E The efflux rate constant of ⁸⁶Rb⁺ in choroid plexus in control conditions and after pretreatment with Ex9-39 or Ex4 (linear regression on data from D), n = 6. F NKCC1-mediated ⁸⁶Rb⁺ efflux rate constants in control settings and after pretreatment with Ex9-39 or Ex4, n = 6. Cpm: counts per minute. The results are presented as mean ± SEM. Statistical significance was evaluated with one-way ANOVA followed by Sidak’s post-hoc test (B and E) or Dunnett’s post-hoc test (C and F). *P < 0.05, **P < 0.01, ***P < 0.001, Non significance is not shown for clarity