Difference in the uptake of glucose in various hippocampal regions

应用冷冻挂载显微放射自显影技术，观察2-脱氧葡萄糖(2-DG)45分钟、葡萄糖15分钟和45分钟后，放射性2-脱氧葡萄糖([1，2-3 H]，[2，6-3 H])和葡萄糖([1-3 H]，[3-3 H])在海马区摄取示踪剂的差异。图像分析仪定量分析银粒。(1)2-DG放射自显影结果显示，杏仁角层腔隙分子的放射性(银粒/mm^2)显著高于其他海马区(p&lt；0.01)，而筋膜门最低(p&lt；0.01)。(2)[1-~3H]葡萄糖和15min[3-~3H]葡萄糖放射自显影显示，齿状突分子层的放射性明显高于其他区域(p&lt；(3)2-DG和45分钟葡萄糖放射自显影显示CA3a区锥体细胞胞体被强烈标记.(4)45分钟葡萄糖放射自显影显示齿状颗粒层的放射性显著高于分子层(p&lt；0.05).这些结果表明，葡萄糖的代谢命运，即主要用于能量生产还是氨基酸合成，取决于海马体的不同结构.另一方面，为了探讨葡萄糖摄取的相关因素，用免疫组织化学方法定量观察了大鼠海马区突触和GFA阳性胶质细胞的分布。结果发现，2-DG放射自显影的放射性与GFA阳性胶质细胞的分布密切相关。也就是说，放射自显影上的颗粒密度越高，该区域的胶质密度就越大。

By freeze-mount microautoradiography, differences in the uptake of tracers from radioactive 2-deoxyglucose ([1,2-^3H],[2,6-^3H]) and glucose ([1-^3H],[3-^3H]) into hippocampal regions were investigated after 45 minutes for 2-deoxyglucose(2-DG), and 15 and 45 minutes for glucose. Silver grains were assessed quantitatively by the image analyzer.(1) The radioactivity (silver grains/mm^2) in the stratum lacunosum-moleculare of the Ammon's horn from 2-DG autoradiograms was significantly higher than that of other hippocampal regions (p<0.01), while lowest in the hilus fascia dentata (p<0.01).(2) autoradiograms of [1-^3H] glucose and 15-min of [3-^3H] glucose showed that the radioactivity in the dentata molecular layer was significantly higher than that of other regions, expect for the stratum lacunosum-moleculare (p<0.05).(3) The 2-DG and 45-min glucose autoradiograms showed the intensely labeled perikarya of pyramidial cells in the CA3a sector.(4) Radioactivity in the dentate granular layer from 45-min autoradiogram of [3-^3H] glucose was significantly higher than that of the molecular layer (p<0.05).These results imply that the metabolic fate of glucose, i.e., whether it is mainly used for energy production or amino acid synthesis depends on each structure of the hippocampus. On the other hand, in order to investigate the factors responisible for glucose uptake, districution of synapses and GFA-positive glia in each hippocampal region was quantitatively observed using immnohistochemical preparations. As the results it was found that the radioactivity from 2-DG autoradiograms was closely related to the distribution of GFA-positive glia. i.e. the higher the grain density on an autoradiogram, the greater the glial density in that region.