Fig. 3.

Effect of riluzole on the high-affinity Na⁺-dependent uptake of glutamate in spinal cord synaptosomes prepared from G93A transgenics and age-matched controls. Glutamate uptake into P2 synaptosomal fractions prepared from disease onset (a) and end-stage (b) G93A rats, together with age-matched controls, was measured in the absence or presence of riluzole (0.1–300 μm) after a 10 min pretreatment with the drug. The net Na⁺-dependent glutamate uptake data were expressed as a percentage of the activity observed in the absence of drug. A significant enhancement of glutamate uptake by riluzole was measured for control tissue (a, b) and G93A transgenic tissue at disease onset (a) (ANOVA;p < 0.05) but not for G93A transgenic tissue at end-stage disease (b).