High resolution autoradiography at the regional topographic level with [14C]2-deoxyglucose and [3H]2-deoxyglucose

After injection of 2-deoxyglucose (2-DG) labeled with tritium or carbon-14, autoradiograms were produced by thaw-mounting 4 micron frozen sections of rat brains on nuclear emulsion-coated slides. The results show that the distribution of radioactivity among different brain regions was similar and that the resolution at the regional topographical level was virtually identical for both compounds. The resolution obtained with the thaw-mounting of thin frozen sections onto nuclear emulsion was considerably greater than the resolution demonstrated in published results in the literature, when carbon-14 or tritium-labeled 2-deoxyglucose were used with 20 micron frozen sections and X-ray film or tritium-sensitive film. The results indicate that section thickness, detection medium and intimacy of contact between section and photographic emulsion influence resolution. At the regional level, the detection medium apparently influences resolution to a greater extent than the energy differences of the beta particles emitted from 14C or 3H. Although diffusion of radiolabeled 2-deoxyglucose and metabolites during the thaw-mounting process precludes single cell resolution of these autoradiograms, the improvement of visualizing regional topographic detail demonstrates that the described technique is a valuable approach with which to study regional 2-DG uptake.