Department of Psychiatry, Columbia University, College of Physicians and Surgeons, New York, New York 10032, USA.
Biol Psychiatry. 2011 Nov 1;70(9):897-904. doi: 10.1016/j.biopsych.2011.06.023.
Serotonergic abnormalities are hypothesized to contribute to obsessive-compulsive disorder (OCD). This study used positron emission tomography with the radioligand [11C]MDL 100907 to examine whether the distribution of serotonin 2A (5-HT(2A)) receptors is altered in OCD.
Nineteen OCD subjects, free of psychiatric medications and depression, and 19 matched healthy subjects underwent positron emission tomography scans following injection of [11C]MDL 100907. Total distribution volumes were derived by kinetic analysis using the arterial input function. Two measures of 5-HT(2A) availability were computed: the ratio at equilibrium of specifically bound radiotracer either to nondisplaceable radiotracer in tissue (BP(ND)) or to unmetabolized tracer in arterial plasma (BP(p)). Groups were compared using a region of interest (ROI) analysis and voxelwise analysis of spatially normalized parametric maps. ROIs included cortical (orbitofrontal, dorsolateral prefrontal, medial prefrontal, anterior cingulate, temporal, parietal, occipital, and insular cortex) and limbic (entorhinal cortex, parahippocampal gyrus, and medial temporal lobe) regions.
No significant group differences were observed in [11C]MDL 100907 BP(ND) or BP(p) in the ROIs or in the voxelwise analysis of BP(ND) maps. There was a significant correlation in the orbitofrontal cortex between [11C]MDL 100907 binding and age of onset, with earlier age of onset associated with higher binding.
Adults with OCD are not characterized as a group by major changes in 5-HT(2A) availability in cortical or limbic brain regions. Further research is warranted to examine potential differences in 5-HT(2A) availability between early- and late-onset OCD and to assess 5-HT(2A) function in relation to other neurotransmitter systems implicated in OCD.
血清素能异常被假设与强迫症（OCD）有关。本研究使用正电子发射断层扫描技术，用放射性配体[11C]MDL 100907，研究 5-羟色胺 2A（5-HT2A）受体的分布是否在 OCD 中发生改变。
19 名未服用精神药物和抑郁症的 OCD 患者和 19 名匹配的健康受试者在注射[11C]MDL 100907 后进行正电子发射断层扫描。通过使用动脉输入函数的动力学分析得出总分布体积。计算了 5-HT2A 可用性的两个指标：组织中特异性结合放射性示踪剂与不可置换放射性示踪剂（BP（ND））或动脉血浆中未代谢示踪剂（BP（p））的平衡时比值。使用感兴趣区（ROI）分析和空间归一化参数图的体素分析比较两组。ROI 包括皮质（眶额、背外侧前额、内侧前额、前扣带、颞叶、顶叶、枕叶和岛叶皮质）和边缘（内嗅皮质、海马旁回和内侧颞叶）区域。
在 ROI 或 BP（ND）图的体素分析中，未观察到[11C]MDL 100907 BP（ND）或 BP（p）在 OCD 组和对照组之间存在显著差异。在眶额皮质中，[11C]MDL 100907 结合与发病年龄之间存在显著相关性，发病年龄较早与结合较高相关。
OCD 成人的皮质或边缘脑区 5-HT2A 可用性无明显变化。需要进一步研究以检查早期和晚期 OCD 之间 5-HT2A 可用性的潜在差异，并评估 5-HT2A 功能与强迫症中涉及的其他神经递质系统的关系。
