Antonini A, Leenders K L, Reist H, Thomann R, Beer H F, Locher J
Positron Emission Tomography Department, Paul Scherrer Institute, Villigen, Switzerland.
Arch Neurol. 1993 May;50(5):474-80. doi: 10.1001/archneur.1993.00540050026010.
Human postmortem and animal experimental results suggest a decline of the cerebral dopaminergic neuronal system with age. In this study, the radiotracer carbon 11-labeled-raclopride and positron emission tomography were applied to determine the effect of age on striatal D2 dopamine receptors in 32 healthy volunteer subjects (age range, 21 to 68 years; median, 31 years). An index of specific 11C-raclopride binding was calculated for putamen, caudate nucleus, and other brain regions in each subject. A significant decrease with age of the index for specific tracer uptake was found in putamen and caudate nucleus. The decrease was steep until 30 years, but slower afterward. After approximately 30 years of age, the decline of specific 11C-raclopride binding in putamen was found to be 0.6% per year. Our results suggest that D2 dopamine receptor binding sites (mainly postsynaptically located) decrease as a consequence of normal aging in parallel with the decline of the presynaptic nigrostriatal dopaminergic neuronal system.
人类尸检和动物实验结果表明，大脑多巴胺能神经元系统会随着年龄增长而衰退。在本研究中，使用放射性示踪剂碳-11标记的雷氯必利和正电子发射断层扫描技术，测定了32名健康志愿者（年龄范围21至68岁；中位数31岁）的年龄对纹状体D2多巴胺受体的影响。计算了每位受试者壳核、尾状核及其他脑区的特异性碳-11雷氯必利结合指数。结果发现，壳核和尾状核的特异性示踪剂摄取指数随年龄显著降低。在30岁之前下降迅速，但之后变慢。大约30岁以后，壳核中特异性碳-11雷氯必利结合的下降幅度为每年0.6%。我们的结果表明，D2多巴胺受体结合位点（主要位于突触后）会因正常衰老而减少，这与突触前黑质纹状体多巴胺能神经元系统的衰退同时发生。
