Thermogenesis in the brown adipose tissue (BAT) is activated by the stimulation of the ventromedial hypothalamic nucleus (VMH). Local warming of the preoptic area (PO) suppresses this response. Injection of the GABA A receptor antagonist bicuculline into the caudal periaqueductal gray (cPAG), where excitatory neurons for BAT thermogenesis are located, did not influence the suppressive effect of PO warming. On the other hand, after bicuculline injection into the raphé pallidus, where excitatory neurons for BAT thermogenesis are also located, VMH stimulation produced BAT thermogenesis even during PO warming. The present results suggest that the inhibitory signal from the PO reaches the raphé pallidus and not the cPAG for the control of BAT thermogenesis.