title: Midbrain dopamine D2/3 receptor binding in schizophrenia.
abstract: Several studies suggest that dysregulation of dopaminergic transmission in the midbrain and thalamus may contribute to the symptomatology of schizophrenia. The objective of this study was to examine the putative alteration of dopamine D(2/3 )receptor densities in the thalamus and midbrain of drug-naïve schizophrenic patients. We used the high-affinity single-photon emission tomography ligand [(123)I]epidepride for imaging D(2/3 )receptor binding sites in six neuroleptic-naïve schizophrenic patients, and seven healthy controls. Schizophrenic symptoms were evaluated by the Positive and Negative Syndrome Scale. Significantly lower D(2/3 )values were observed in the midbrain of patients with schizophrenia compared to controls (P = 0.02). No statistically significant difference was observed in the thalamus between two groups. Negative correlations were found between thalamic D(2/3 )receptor binding and general psychopathological schizophrenic symptoms (r from -0.78 to -0.92). These observations implicate altered dopaminergic activity in the midbrain of schizophrenic patients.
authors.affiliation: Department of Forensic Psychiatry, University of Kuopio, Niuvanniemi Hospital, 70240, Kuopio, Finland. heli.tuppurainen@niuva.fi
authors.forename: Heli
authors.initials: H
authors.lastname: Tuppurainen
authors.forename: Jyrki T
authors.initials: JT
authors.lastname: Kuikka
authors.forename: Mikko P
authors.initials: MP
authors.lastname: Laakso
authors.forename: Heimo
authors.initials: H
authors.lastname: Viinamäki
authors.forename: Minna
authors.initials: M
authors.lastname: Husso
authors.forename: Jari
authors.initials: J
authors.lastname: Tiihonen
mesh_terms: D000328:Adult; D001549:Benzamides; D002531:Cerebellum / Q000000981:diagnostic imaging / Q000378:metabolism; D003287:Contrast Media; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008636:Mesencephalon / Q000000981:diagnostic imaging / Q000378:metabolism*; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D050637:Receptors, Dopamine D3 / Q000378:metabolism*; D012559:Schizophrenia / Q000000981:diagnostic imaging / Q000378:metabolism*; D013788:Thalamus / Q000000981:diagnostic imaging / Q000378:metabolism; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D001549:Benzamides; D003287:Contrast Media; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; C063525:epidepride