Assessment of Central Dopamine Release by Exercise in Hunian in vivo.

D_2PET显像技术是一种新的神经科学研究方法。我们应用这种技术来评估DA释放持久测力计运动。我们推测，以前的研究未能揭示DA释放的运动可能是从技术问题。他们在运动结束后测量了D_2受体的分布。通过使用改进的测力计，允许骑自行车，而躺在PET沙发上，我们进行了雷氯必利PET同时在运动。为了尽量减少头部运动，由于骑自行车，我们使用了塑料面罩，为适形放射治疗开发的每个主题。此外，使用SPM 5（功能成像实验室，伦敦）中配备的图像对准算法对头部运动进行数学校正。8名健康男性志愿者，年龄21.4±2.0（s.d.）多年来，他一直在研究。他们进行了50分钟的中等强度（VO 2 Max 35〜60%）的测力计运动。在<11>运动开始后20分钟静脉内注射雷氯必利，然后使用具有散射校正的3D正电子照相机（Shimadzu 2400 W）收集连续PET图像。将ROI放置在每侧的尾状核、壳核和小脑。以小脑为参照组织，采用简化的参照组织模型（Lammersma和古恩）、Logan无创模型和Ichise模型计算雷氯必利与D_2受体的结合电位（BP）。运动时纹状体的BP显著降低（-12.9至17.0%，P&lt;0.01），与对照条件（仅躺在PET床上）相比。尾状核和壳核之间以及两个半球之间的减少几乎相似。结果强烈支持DA释放在这个测力计运动条件。我们大脑中的多巴胺释放可以解释运动后的清爽感觉及其习惯。

Assessment of central dopamine (DA) release in vivo in human using D_2 PET mapping is a novel technique for neuroscience. We applied this technique to assess DA release by enduring ergometer exercise. We hypothesized that failure of the previous studies to reveal DA release by exercise may be from technical problems. They measured D_2 receptor distribution after completion of exercise. By using a modified ergometer that allows bicycling while lying on PET couch, we carried out raclopride PET simultaneously during exercise. To minimize head movements due to bicycling, we used a plastic face mask for each subject developed for conformal radiotherapy. In addition head movements were mathematically corrected using an image alignment algorithm equipped in SPM5 (Functional Imaging Laboratory, London). Eight healthy male volunteers aged 21.4±2.0 (s.d.) years collaborated the study. They made an ergometer exercise of moderate intensity (VO2Max 35〜60%) for 50 minutes. [^<11>C]Raclopride was injected intravenously at 20 minutes after start of the exercise and then a sequential PET images were collected using 3D positron camera (Shimadzu 2400W) with scatter correction. ROIs were placed at the caudate, putamen, and cerebellum of each side. Choosing cerebellum as a reference tissue we calculated raclopride binding potential (BP) to D_2 receptors using the simplified reference tissue model (Lammersma and Gunn), Logan noninvasive model, and Ichise model. The BP in the striatum were significantly reduced at exercise (-12.9〜17.0%, P<0.01) when compared to a control condition (lying on PET couch only). The reductions were almost similar between the caudate and the putemen and between hemispheres. The results strongly support DA release at this ergometer exercise condition. Dopamine release in our brain may explain refreshing feeling after exercise and its habituations.