Studies on Thermoregulatory Capability in the

i n the rabbits devoid of pre-optic and anterior hypothalamic (PO/AH) regions. Bilateral PO/AH lesions in male rabbits were accomplished using electrolytic procedure. And thermoregulatory capabilities before and after PO/AH lesions were compared. In control rabbits, with the change in ambient temperature (Ta), the ear skin temperature (Tea) changed in the same direction. The change in rectal temperature (Tre) was small. In one-week-lesioned rabbit, the change of Tre was great when heated, but Tre was stable to cold stress. In two-weeks lesioned rabbit, Tre, inspite of Ta change, was quite stable: to the extent that it was comparable to the control rabbits. Therefore, these results should be interpreted as presenting the recovery of thermoregulatory functions after the PO/AH lesions. It is concluded that, without PO/AH participation, extrahypo-thalamic thermosensitive tissues were the places endowed with these thermoregulatory functions. K ey words: PO/AH lesioned rabbit, Thermoregulatory capability, Cutaneous vasodilation and vasoconstriction, Extrahypothalamic temperature regulatio