Tyrosine augments clozapine-induced dopamine release in the medial prefrontal cortex of the rat in vivo: effects of access to food.

It has been reported that tyrosine administration augments clozapine-induced dopamine (DA) release in the medial prefrontal cortex (MPFC). To characterize this effect and exclude possible confounds, we conducted a series of studies in which microdialysate collection started 24 h after probe implantation, a time at which most collected DA is thought to be impulse mediated. Tyrosine (25 or 50 mg/kg IP) administered 30 min after clozapine (10 mg/kg IP) augmented clozapine-induced MPFC but not striatal DA release. While tyrosine potentiation was also evident in both fasted animals and those with free access to food, the effective doses of tyrosine varied. We confirm that tyrosine administration can potentiate clozapine-induced MPFC DA release but note that the effect is not evident across all doses and conditions.