THERMOGENESIS IN BROWN ADIPOSE-TISSUE IS ACTIVATED BY ELECTRICAL-STIMULATION OF THE RAT DORSAL RAPHE NUCLEUS

Brainstem mechanisms involved in the central control of thermogenesis in brown adipose tissue (BAT) were investigated, in urethane-anaesthet ized rats, by observing changes in the temperature of interscapular BA T following electrical stimulation of sites in the dorsal raphe nucleu s (DRN). Large increases in temperature could be produced by single 30 s stimulation trains. The magnitude of the temperature increase grew as a function of both current and frequency. Non-linear temporal summa tion was observed when near-threshold trains were delivered in close s uccession. These results are consistent with the view that ascending p rojections from the DRN relay thermal information to the basal forebra in and hypothalamus.