Species difference in circadian [14C]2-deoxyglucose uptake by suprachiasmatic nuclei

Hamsters exhibited a circadian variation in metabolic activity determined by [14C]2-deoxyglucose uptake in the suprachiasmatic nuclei, as has been previously reported for rats. The 13-line ground squirrel, a diurnal rodent, did not show a circadian variation in metabolic activity. The data are consistent with the hypothesis that there is a basic difference in the functional organization of the suprachiasmatic nuclei in nocturnal and diurnal animals.