Ouchi Y, Fukuyama H, Ogawa M, Yamauchi H, Kimura J, Magata Y, Yonekura Y, Konishi J
Department of Neurology, Faculty of Medicine, Kyoto University, Japan.
J Cereb Blood Flow Metab. 1996 Jan;16(1):34-41. doi: 10.1097/00004647-199601000-00004.
To investigate the influence of cholinergic projections from the basal forebrain on cerebral cortex metabolism, we evaluated the cerebral metabolic rate of glucose (CMRGlu) after selective inhibition of cholinergic neurons in the rat basal forebrain using the pyruvate dehydrogenase complex inhibitor 3-bromopyruvic acid (BPA), and compared the results with those obtained after lesioning the basal forebrain with ibotenic acid, as well as with those from a sham-operated control group. CMRGlu was measured using positron emission tomography (PET) with [18F]-2-fluoro-2-deoxy-D-glucose (FDG). Three days after surgery, CMRGlu and k3 (phosphorylation of FDG) were reduced similarly in the frontal cortex on the BPA-injected side and in the ibotenic acid-treated group, whereas K1 (transport rate of FDG from the plasma to brain) showed no marked changes. At 3 weeks postoperatively, the CMRGlu and k3 of the frontal cortex in both groups recovered to levels similar to those of the sham-operated group. The main difference between the BPA and ibotenic acid groups was that CMRGlu showed mild reduction on the side contralateral to the operation in the former, while such reduction was confined to the ipsilateral hemisphere in the latter. The present results indicate that the cholinergic system in the basal forebrain regulates cerebral cortex glucose metabolism through direct excitation of cortical neurons.
为了研究基底前脑胆碱能投射对大脑皮层代谢的影响，我们使用丙酮酸脱氢酶复合物抑制剂3-溴丙酮酸（BPA）选择性抑制大鼠基底前脑胆碱能神经元后，评估了大脑葡萄糖代谢率（CMRGlu），并将结果与用鹅膏蕈氨酸损伤基底前脑后获得的结果以及假手术对照组的结果进行了比较。使用[18F]-2-氟-2-脱氧-D-葡萄糖（FDG）通过正电子发射断层扫描（PET）测量CMRGlu。手术后三天，注射BPA一侧的额叶皮层和鹅膏蕈氨酸处理组的CMRGlu和k3（FDG的磷酸化）同样降低，而K1（FDG从血浆到脑的转运速率）无明显变化。术后3周，两组额叶皮层的CMRGlu和k3恢复到与假手术组相似的水平。BPA组和鹅膏蕈氨酸组的主要区别在于，前者手术对侧的CMRGlu有轻度降低，而后者这种降低局限于同侧半球。目前的结果表明，基底前脑的胆碱能系统通过直接兴奋皮层神经元来调节大脑皮层葡萄糖代谢。
