The metabolic consequence of visual deprivation in the rat

The effects of visual conditions during rearing were measured metabolically in adult rats. Quantitative 2-deoxy[14C]glucose autoradiography was performed on pigmented rats raised from birth in either total darkness or ambient laboratory light. One eye was enucleated on the day of the experiment and glucose utilization was determined in the presence of ambient laboratory light or total darkness. The optic centers of subjects raised in total darkness and tested in ambient light had the highest rates of glucose utilization compared to any of the other 3 groups. The lateral geniculate nucleus (pars dorsalis and pars ventralis), lateral posterior nucleus and superior colliculus exhibited the greatest changes. Normally reared rats showed very little metabolic difference between total darkness and ambient laboratory light. These results demonstrated that dark rearing increases the rates of glucose utilization in the rodent visual system. However, the extent of these increases is dependent upon stimulus conditions during measurement and the optic center being measured.