Rocher Anne B, Chapon Françoise, Blaizot Xavier, Baron Jean-Claude, Chavoix Chantal
INSERM U320, Centre Cyceron, Caen, France.
Neuroimage. 2003 Nov;20(3):1894-8. doi: 10.1016/j.neuroimage.2003.07.002.
It is classically recognized that regional cerebral glucose consumption (CMRglc), as measured by positron emission tomography (PET) and [18F]-2-fluorodeoxyglucose (FDG), is a precise index of the integrated local neuronal activity. However, despite extensive use of the FDG-PET method, the significance of the measured CMRglc has been little addressed so far. In the present study, we aimed for the first time to test whether resting-state CMRglc is directly related to synaptic density. To this end, we investigated in the baboon the relationships between CMR(glc) and the levels of synaptophysin (SY), a presynaptic protein classically used to assess synaptic density. CMR(glc), measured in vivo by FDG-PET at the resting-state, and SY levels, assessed postmortem by the Western blot technique, were quantified in seven brain areas of five baboons. By applying these two techniques to the same animals, we found significant positive correlations between CMR(glc) and SY levels, across all regions and all animals, as well as within individual baboons. These findings strongly support the hypothesis that resting-state CMR(glc) reflects integrated synaptic activity.
传统上认为，通过正电子发射断层扫描（PET）和[18F]-2-氟脱氧葡萄糖（FDG）测量的局部脑葡萄糖代谢率（CMRglc）是局部神经元综合活动的精确指标。然而，尽管FDG-PET方法被广泛使用，但迄今为止，所测量的CMRglc的意义很少得到探讨。在本研究中，我们首次旨在测试静息状态下的CMRglc是否与突触密度直接相关。为此，我们在狒狒中研究了CMR（glc）与突触素（SY）水平之间的关系，SY是一种经典的用于评估突触密度的突触前蛋白。通过FDG-PET在静息状态下体内测量CMR（glc），并通过蛋白质印迹技术在死后评估SY水平，对5只狒狒的7个脑区进行了量化。通过将这两种技术应用于同一动物，我们发现在所有区域、所有动物以及单个狒狒体内，CMR（glc）与SY水平之间存在显著的正相关。这些发现有力地支持了静息状态下的CMR（glc）反映突触综合活动这一假说。
