title: Regional dopamine synthesis in patients with schizophrenia using L-[beta-11C]DOPA PET.
abstract: The dopamine hypothesis has been the most widely known theory concerning schizophrenia. However, the exact mechanism including presynaptic dopaminergic activity and its relationship with symptom severity still remains to be revealed. We measured presynaptic dopamine synthesis using positron emission tomography (PET) with L-[beta-(11)C]DOPA in 18 patients with schizophrenia (14 drug-naive and 4 drug-free patients) and 20 control participants. Dopamine synthesis rates, expressed as k(i) values, were obtained using a graphical method, and the occipital cortex was used as reference region. Regions of interest were placed on the prefrontal cortex, temporal cortex, anterior cingulate, parahippocampus, thalamus, caudate nucleus, and putamen. Psychopathology was assessed with the Positive and Negative Symptom Scale (PANSS). We found significantly higher k(i) values in patients than in controls in the left caudate nucleus, but not in the other regions. The k(i) values in the thalamus exhibited a significant positive correlation with the PANSS total scores. Furthermore, a significant positive correlation was observed between the PANSS positive subscale scores and k(i) values in the right temporal cortex. Patients with schizophrenia showed higher dopamine synthesis in the left caudate nucleus, and dopaminergic transmission in the thalamus and right temporal cortex might be implicated in the expression of symptoms in schizophrenia.
authors.affiliation: Molecular Neuroimaging Group, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan.
authors.forename: Shoko
authors.initials: S
authors.lastname: Nozaki
authors.forename: Motoichiro
authors.initials: M
authors.lastname: Kato
authors.forename: Harumasa
authors.initials: H
authors.lastname: Takano
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ito
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Takahashi
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Arakawa
authors.forename: Masaki
authors.initials: M
authors.lastname: Okumura
authors.forename: Yota
authors.initials: Y
authors.lastname: Fujimura
authors.forename: Ryohei
authors.initials: R
authors.lastname: Matsumoto
authors.forename: Miho
authors.initials: M
authors.lastname: Ota
authors.forename: Akihiro
authors.initials: A
authors.lastname: Takano
authors.forename: Akihiko
authors.initials: A
authors.lastname: Otsuka
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Yasuno
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Okubo
authors.forename: Haruo
authors.initials: H
authors.lastname: Kashima
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Suhara
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002250:Carbon Radioisotopes; D016009:Chi-Square Distribution; D004298:Dopamine / Q000096:biosynthesis*; D015259:Dopamine Agents / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D007980:Levodopa / Q000493:pharmacokinetics; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000000981:diagnostic imaging* / Q000378:metabolism*; D055815:Young Adult
chemical_list: D002250:Carbon Radioisotopes; D015259:Dopamine Agents; D007980:Levodopa; D004298:Dopamine