The medial prefrontal cortex mediates 3-methoxytyramine-induced behavioural changes in rat.
L-3,4-Dihydroxyphenylalanine (L-DOPA) remains a common treatment for Parkinson's disease; however, side effects (i.e., dyskinesia and hallucinations) also remain problematic. We recently reported that the dopamine metabolite 3-methoxytyramine causes stereotypy in rats via dopamine receptors, raising the possibility that 3-methoxytyramine is involved in the adverse side effects of chronic L-DOPA treatment. Thus, the present study examined the sites of 3-methoxytyramine action in the rat brain. After intracerebroventricular administration of 3-methoxytyramine, significantly more neurones expressed c-Fos in mesocortico-limbic dopamine areas including frontal cortex, medial prefrontal cortex, parietal cortex, piriform cortex, the nucleus accumbens shell, and ventral tegmental area. 3-Methoxytyramine injection into the medial prefrontal cortex specifically resulted in behavioural changes characteristic of those elicited by the more general intracerebroventricular injection of 3-methoxytyramine. This suggests that the medial prefrontal cortex mediates the 3-methoxytyramine-induced behavioural changes and that a reduction of its action there may alleviate the adverse effects of chronic L-DOPA treatment.
Nakazato
Taizo
T
Department of Physiology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, Japan. nakazato@med.junitendo.ac.jp
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D004298:Dopamine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D007150:Immunohistochemistry; D007276:Injections, Intraventricular; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar
D016760:Proto-Oncogene Proteins c-fos; C001746:3-methoxytyramine; D004298:Dopamine