Fig. 5.

Dose-dependent effect of dialysis of three doses of RP (1 mM, n = 4; 2 mM, n = 3; 3 mM, n = 7) and three doses of SPA (133 μM, n = 7; 267 μM, n = 5; 500 μM, n = 6) on absolute change in effluent GABA and SP concentration. Neither RP nor SPA concentration were significant predictors of the change in GABA levels (A and B) (P ≥ 0.355). RP concentration was a significant predictor of the change in SP (C) (P < 0.001, R²=0.915); SPA concentration was also a significant predictor of the change in SP (D) (P = 0.003, R²=0.442). x Axis indicates antagonist concentration; y axis indicates change in effluent neurochemical concentration. P and R² values are results from simple linear regression analyses.