title: Tyrosine augments clozapine-induced dopamine release in the medial prefrontal cortex of the rat in vivo: effects of access to food.
abstract: 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.
authors.affiliation: Psychiatry Service 116A(B), Louis Stokes Cleveland Veterans Affairs Medical Center, 10000 Brecksville Road, Brecksville, OH 44141, USA. george.jaskiw@case.edu
authors.forename: George E
authors.initials: GE
authors.lastname: Jaskiw
authors.forename: Catherine
authors.initials: C
authors.lastname: Simpson
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Bongiovanni
authors.forename: Bryan K
authors.initials: BK
authors.lastname: Yamamoto
mesh_terms: D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology; D003024:Clozapine / Q000494:pharmacology*; D004298:Dopamine / Q000096:biosynthesis / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions / Q000502:physiology; D004357:Drug Synergism; D004435:Eating / Q000187:drug effects / Q000502:physiology; D045604:Extracellular Fluid / Q000187:drug effects / Q000378:metabolism; D017551:Microdialysis; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism; D009434:Neural Pathways / Q000187:drug effects* / Q000378:metabolism; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D012559:Schizophrenia / Q000378:metabolism / Q000503:physiopathology; D014443:Tyrosine / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D014150:Antipsychotic Agents; D014443:Tyrosine; D003024:Clozapine; D004298:Dopamine