COLD-DEFENSE FUNCTION OF BROWN ADIPOSE-TISSUE DURING SLEEP

Rats with chronically implanted electroencephalograph scalp electrodes and thermistors were exposed to 24 and 4-degrees-C ambient temperatur es during the light hours before and after acclimation to 4-degrees-C ambient temperature for 9 days. During synchronized sleep, deep inters capular temperature was higher at 4-degrees-C than at 24-degrees-C bot h before and after acclimation to cold. After ablation of brown adipos e tissue, deep interscapular temperature was lower at 4-degrees-C than at 24-degrees-C during synchronized sleep. In the presence of brown a dipose tissue, deep interscapular temperature decreased sharply during desynchronized sleep at 4-degrees-C both before and after acclimation to cold. This decrease was subsequent to and correlated with an incre ase in the temperature of the nasal mucosa. The decrease in deep inter scapular temperature during desynchronized sleep at 4-degrees-C ambien t temperature was markedly reduced by ablation of the interscapular br own adipose tissue.