Regional dopamine synthesis in patients with schizophrenia using L-[beta-11C]DOPA PET.
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.
Nozaki
Shoko
S
Molecular Neuroimaging Group, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan.
Kato
Motoichiro
M
Takano
Harumasa
H
Ito
Hiroshi
H
Takahashi
Hidehiko
H
Arakawa
Ryosuke
R
Okumura
Masaki
M
Fujimura
Yota
Y
Matsumoto
Ryohei
R
Ota
Miho
M
Takano
Akihiro
A
Otsuka
Akihiko
A
Yasuno
Fumihiko
F
Okubo
Yoshiro
Y
Kashima
Haruo
H
Suhara
Tetsuya
T
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
D002250:Carbon Radioisotopes; D015259:Dopamine Agents; D007980:Levodopa; D004298:Dopamine