Decreased dopamine D2 receptor binding in the anterior cingulate cortex in schizophrenia.
BACKGROUND
The clinical efficacy of dopamine D2 receptor antagonism on the psychotic symptoms of schizophrenia has been widely demonstrated. However, most in vivo imaging studies have not been able to detect significant changes in striatal D2 receptors in schizophrenia. On the other hand, a number of studies have reported abnormalities in the cerebral cortex of schizophrenia. The aim of this study was to examine the extrastriatal D2 receptors of patients with schizophrenia.


METHODS
Eleven drug-naive male patients with schizophrenia were examined with positron emission tomography using carbon 11-labeled FLB 457. Symptoms were assessed using the Brief Psychiatric Rating Scale. Eighteen healthy controls were used for comparison. Region-of-interest analysis was performed using the reference tissue method, and binding potential (BP) was used for the index of dopamine D2 receptor binding.


RESULTS
The BP value was significantly lower, by about 12.5%, in the anterior cingulate cortex in drug-naive patients with schizophrenia than in healthy controls. A significant negative correlation was observed between BP in the anterior cingulate cortex and the positive symptom score on Brief Psychiatric Rating Scale.


CONCLUSIONS
The lower BP values indicate fewer D2 receptors in the anterior cingulate cortex in patients with schizophrenia. Alterations in D2 receptor function in the extrastriatal region may underlie the positive symptoms of schizophrenia.
Suhara
Tetsuya
T
Division of Advanced Technology for Medical Imaging, National Institute of Radiological Sciences, 9-1, Anagawa 4-Chome, Inage-ku, Chiba-shi, 263-8555 Japan. suhara@nirs.go.jp
Okubo
Yoshiro
Y
Yasuno
Fumihiko
F
Sudo
Yasuhiko
Y
Inoue
Makoto
M
Ichimiya
Tetsuya
T
Nakashima
Yoshifumi
Y
Nakayama
Kazuhiko
K
Tanada
Shuji
S
Suzuki
Kazutoshi
K
Halldin
Christer
C
Farde
Lars
L
D000328:Adult; D001931:Brain Mapping; D018492:Dopamine Antagonists / Q000493:pharmacokinetics; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D011759:Pyrrolidines / Q000493:pharmacokinetics; D017448:Receptors, Dopamine D2 / Q000502:physiology*; D012016:Reference Values; D012457:Salicylamides / Q000493:pharmacokinetics; D012559:Schizophrenia / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D014055:Tomography, Emission-Computed
D018492:Dopamine Antagonists; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2; D012457:Salicylamides; C065065:FLB 457