Talvik Mirjam, Nordström Anna-Lena, Okubo Yoshiro, Olsson Hans, Borg Jacqueline, Halldin Christer, Farde Lars
Karolinska Institute, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital R4, SE-171 76 Stockholm, Sweden.
Psychiatry Res. 2006 Dec 1;148(2-3):165-73. doi: 10.1016/j.pscychresns.2006.05.009. Epub 2006 Nov 13.
The aim was to test the dopamine hypothesis of schizophrenia in a further analysis of D(2)-like dopamine binding using the radioligand [(11)C]raclopride and high resolution 3-dimensional (3D) PET. Eighteen drug-naive patients with schizophrenia and seventeen control subjects were examined. The D(2) binding potential (BP) in the putamen, the caudate and the thalamus was calculated using the simplified reference tissue model. The volume of regions of interest was controlled for by MRI. Symptoms were rated with the Positive and Negative Syndrome Scale for Schizophrenia (PANSS). No significant group differences were found for D(2) BP in the putamen or in the caudate and there was no significant hemispheric difference for any region. In the right thalamus the D(2) BP was significantly lower in patients as compared to control subjects, whereas a numerical difference did not reach statistical significance for the left thalamus. There was no significant correlation between D(2) BP and total PANSS score in any region. There was a highly significant age effect in the caudate and in the putamen, but not in the thalamus. In this relatively large PET study of exclusively drug-naive schizophrenic patients, a lower D(2) BP in the right thalamus was found in the patient group. This finding is in agreement with two previous studies in Sweden and in Japan using the high-affinity radioligand [(11)C]FLB 457 and provide further support for a role of dopamine in the thalamus related to the pathophysiology of schizophrenia.
目的是通过使用放射性配体[¹¹C]雷氯必利和高分辨率三维（3D）正电子发射断层扫描（PET）对D₂样多巴胺结合进行进一步分析，来检验精神分裂症的多巴胺假说。对18名未服用过药物的精神分裂症患者和17名对照受试者进行了检查。使用简化参考组织模型计算壳核、尾状核和丘脑的D₂结合潜能（BP）。通过磁共振成像（MRI）控制感兴趣区域的体积。使用精神分裂症阳性和阴性症状量表（PANSS）对症状进行评分。壳核或尾状核的D₂ BP在两组之间未发现显著差异，且任何区域均未发现显著的半球差异。与对照受试者相比，患者右侧丘脑的D₂ BP显著降低，而左侧丘脑的数值差异未达到统计学显著性。任何区域的D₂ BP与PANSS总分之间均无显著相关性。尾状核和壳核存在高度显著的年龄效应，但丘脑中没有。在这项专门针对未服用过药物的精神分裂症患者的相对大型PET研究中，患者组右侧丘脑的D₂ BP较低。这一发现与瑞典和日本之前两项使用高亲和力放射性配体[¹¹C]FLB 457的研究结果一致，并为多巴胺在与精神分裂症病理生理学相关的丘脑中的作用提供了进一步支持。
