Department of Psychiatry, Columbia University College of Physicians & Surgeons, New York, NY, USA.
Depress Anxiety. 2013 Mar;30(3):197-206. doi: 10.1002/da.22019. Epub 2013 Feb 13.
Brain serotonin-1A receptors (5-HT1A ) are implicated in anxiety. We compared regional brain 5-HT1A binding in medication-free participants with posttraumatic stress disorder (PTSD) and healthy volunteers using fully quantitative positron emission tomography (PET) methods.
Twenty patients with DSM-IV PTSD (13 with comorbid major depressive disorder, [MDD]) and 49 healthy volunteers underwent PET imaging with 5-HT1A antagonist radioligand [C-11]WAY100635. Arterial blood sampling provided a metabolite-corrected input function and the concentration of free ligand in plasma (fP ) for estimation of regional binding potential, BPF ( = Bavailable / KD ). Linear mixed modeling compared BPF between groups across regions of interest (ROIs).
The PTSD group had higher 5-HT1A BPF across brain ROIs (P = .0006). Post hoc comparisons showed higher 5-HT1A BPF in PTSD in all cortical ROIs (26-33%), amygdala (34%), and brainstem raphe nuclei (43%), but not hippocampus. The subgroup of seven PTSD patients without comorbid MDD had higher 5-HT1A BPF compared with healthy volunteers (P = .03).
This is the first report of higher brainstem and forebrain 5-HT1A binding in vivo in PTSD. The finding is independent of MDD. PTSD and MDD have in common an upregulation of 5-HT1A binding including midbrain autoreceptors that would favor less firing and serotonin release. This abnormality may represent a common biomarker of these stress-associated brain disorders.
脑 5-羟色胺-1A 受体（5-HT1A）与焦虑有关。我们使用完全定量正电子发射断层扫描（PET）方法比较了无药物治疗的创伤后应激障碍（PTSD）患者和健康志愿者的大脑 5-HT1A 结合情况。
20 名 DSM-IV PTSD 患者（13 名合并有重度抑郁障碍[MDD]）和 49 名健康志愿者接受了 5-HT1A 拮抗剂放射性配体[C-11]WAY100635 的 PET 成像。动脉血样采集提供了一个代谢校正的输入函数和血浆中游离配体的浓度（fP），用于估计区域结合潜力，BPF（=Bavailable/KD）。线性混合模型比较了两组之间的感兴趣区域（ROI）的 BPF。
PTSD 组大脑 ROI 中的 5-HT1A BPF 更高（P=0.0006）。事后比较显示，PTSD 组所有皮质 ROI（26-33%）、杏仁核（34%）和脑干中缝核（43%）的 5-HT1A BPF 更高，但海马体除外。没有合并 MDD 的七名 PTSD 患者亚组与健康志愿者相比，5-HT1A BPF 更高（P=0.03）。
这是首次报道 PTSD 患者大脑中脑和前脑 5-HT1A 结合增加。这一发现与 MDD 无关。PTSD 和 MDD 共同存在 5-HT1A 结合上调，包括中脑自身受体，这有利于减少放电和 5-羟色胺释放。这种异常可能代表这些与应激相关的脑部疾病的共同生物标志物。
