BODY lEMPERATURE AND FOOD AND WATER INTAKE 371 



favour of a " glucostatic " mechanism in the ventromedial hypothalamus 

 maintaining the short-term regulation (Mayer, 1952 and 1955). The long- 

 term regulation may on the other hand be dependent on a " lipostatic " 

 mechanism (Kennedy, 1953 ; Hervey, 1959). 



On the basis of studies of the intimate relation that exists between body 

 temperature and food intake Brobeck (1948, 1960) has suggested that heat 

 may also be an important factor in the short term regulation of food 

 intake. According to this " thermostatic " theory, hunger is reduced by a 



r~ warrpitna- I 



Brain 

 C 



60- 



45- 



35 



L"°^"J 





5 



EATING 



EAT. 



Ear 



25 



15 



20 



25 



35 MIN. 



Fig. 9. Results of warming the preoptic region and rostral hypothalamus in the 

 previously hungry animal. Brain temperature was recorded close to the 

 surface of the thermode. The goat was fed hay at the beginning of the experiment 

 and had free access to water except during the first period of central warming. 

 During the periods of warming eating stopped simultaneously with the onset of 

 peripheral vasodilatation (rise of ear surface temperature), and started again 

 when ear surface temperature had begun to fall after discontinuation of central 

 warming. The perfusion of the thermode with warm water induced a strong 

 urge to drink. During the first period of central warming, when the water 

 container was temporarily removed, it was evidenced by the animal's licking 

 the drops of water coming out of the outlet tubing o\'' the thermode (" thirst ") 

 and later by the repeated drinking of large amounts of water during the periods 

 of central warming. (From Andersson and Larsson, 1961.) 



rise in temperature in the ventromedial hypothalamus (the '' satiety centre ") 

 or by stimulating heat sensitive neurons in the anterior hypothalamus (the 

 " heat loss centre "). Observations made in experiments involving warm- 

 ing and cooling of the preoptic region and anterior hypothalamus of the 

 goat speak in favour of the latter possibility (Andersson and Larsson, 

 1961 ; Andersson, Gale and Sundsten, 1962a), Warming of the anterior 



