368 



ANDIRSSON AND OTHERS 



Hoebel and Teitelbaum, 1962). It therefore seems fully justitied to call the 

 ventromedial hypothalamus a " satiety centre " in a physiologial sense. 

 More doubtful is whether the term " hunger '' or " appetite centre " could 

 really be used for the lateral hypothalamus. Electrical stimulation of the 

 lateral hypothalamus may elicit stimulus bound eating (Delgado and 

 Anand, 1953 ; Larsson, 1954) and bilateral lesions in this region may lead 

 to temporary or even permanent aphagia (Anand and Brobeck, 1951, 

 Teitelbaum, 1961, Morgane, 1961a). The lateral hypothalamus is however 



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TIME 8 16 34 B 16 ?4 8 f6 



Fig. 6. A, Thyroid response (plasma PBP^^) to ruminal cooling (RC). B, 



Inhibition of this response by preoptic warming (preopt. w.) (to 40.8°C). 

 Note subsequent rise in plasma PBP'^^ and onset of shivering when preoptic 

 warming was stopped. C, Ruminal cooling repeated without preoptic warm- 

 ing, The dose of carrier free V^^ (60 //c) given 3 days prior to the experiment. 

 Time of day recorded on abscissa. (From Andersson, Ekman, Gale, and 



Sundsten, 1962c.) 



a passage for numerous nerve tracts and fibres connecting the frontal brain, 

 the basal ganglia, and the temporal lobes with the hypothalamus and lower 

 parts of the brain stem. The nerve cells present in this region are relatively 

 few and scattered in this network of fibres. From the anatomical point of 

 view the lateral hypothalamus thus by no means has the character of a 

 " centre " and it may be questioned whether one can here talk about a 

 " hunger centre " even in the physiological sense (Morgane, 1961b). 

 Some of the tracts descending or crossing through the lateral hypothalamus 



