BODY TEMPERATURE AND FOOD AND WATER INTAKE 



367 



Raiison, 1940) vshich in lurn is the consequence of a conspicuous hyper- 

 phagia (Brobeck, Tepperman and Long, 1943). One explanation for this 

 hyperphagia would be that the destruction of the ventromedial hypothala- 

 mus intensifies the hunger " drive ". Teitelbaum and co-workers (1955, 

 1961) have however shown that the hunger " drive '' decreases due to a 



r-'^o 



Fig. 5. A comparison of the thyroid activities caused by general cold stress 

 (Ruminal cooling) and by local cooling of the preoptic " heat loss centre " 

 (Central cooling). Thyroid activity is measured in per cent of the total 40 C 

 dose of P''^ given to the animal. 



PBP'^^ plasma protein bound l^^K 

 (From Andersson, Ekman, Gale and Sundsten, 1962b.) 



lesion in the ventromedial hypothalamus, but the lesioned animals eat 

 excessively because their ability to gain satiety during feeding has become 

 markedly reduced. Correspondingly, the hunger " drive " disappears 

 completely when the ventromedial hypothalamus is stimulated (Olds, 1958 ; 



