Comparative rates of local cerebral glucose utilization in the visual system of conscious albino and pigmented rats

We measured local cerebral glucose utilization by means of the [14C]deoxyglucose technique in normal, conscious albino Sprague-Dawley and pigmented Norway rats in the ambient light of the laboratory. There were no differences between the two strains in any structures except those of the visual system. The rates of glucose utilization in all components of the visual system were lower in the albino than in the pigmented rats. The affected structures and percent differences were as follows: visual cortex (17%); stratum griseum superficialis (28%), stratum opticum (17%), and stratum lemnisci (10%) of the superior colliculus; dorsal nucleus (34%) and ventral nucleus (33%) of the lateral geniculate body; and posterolateral thalamus (10%). All differences were statistically significant (p < 0.05) except those in the striatum lemnisci and posterolateral thalamus. These results indicate that the known aberrant neurophysiologic function of the visual system of the albino rats is paralleled by alterations in metabolic activity of its component structures.