Fig. 4.

Effect of intraperitoneal injections of 30 mg/kg ketamine on the extracellular levels of dopamine (n = 7) and glutamate (n = 5) in the striatum. This treatment caused a trend toward an increase in extracellular levels of glutamate; however, because of high variability, there was no statistically significant effect. The striatal extracellular levels of dopamine did increase after the injection of 30 mg/kg ketamine (p < 0.01); however, this increase was significantly smaller than that observed in the prefrontal cortex (demonstrated on Fig. 3, p < 0.005).