CENTRAL NERVOUS REGULATION OF BODY TEMPERATURE 



1179 



RECr 

 ■femp 



C40° 



39 



38 



Shiv. 



Temp 

 2S' 



15 



RCSP 

 Role 



200 



150 



100 



SO 



0.7SV 



w : 



IV 



0.7SV I SV 



wmm -WNmm- 



-n-^ 



yv_i 



10 



20 



30 



40 



50 



120 MINUTES 



FIG. 6. Effect of electrical stim- 

 ulation of the hypothalamic 'heat 

 loss center' in the unanesthetized 

 goat on shivering, ear tempera- 

 ture and respiratory rate. Elec- 

 trodes are inserted by the Hess 

 technique. Duration and voltage 

 of stimulation are on top. Double 

 lining of respiratory rate curve 

 indicates panting. Body tempera- 

 ture was lowered at (W) by giv- 

 ing 3.5 1. of cold (io°C) water into 

 the rumen; this induced shiver- 

 ing. [From Andersson el al. (4).] 



Ejfecls of Chronic Destruction 



Chronic mesencephalic transection, caudal to the 

 tuber cinereum, was found in 1914 by Isenschniid and 

 co-workers (117, 118) to eliminate effective tempera- 

 ture regulation in the rabbit. A similar result in the 

 cat was obtained in 1922 by Bazett & Penfield (22); 

 it was also found in birds (178). Chronic high spinal 

 transection in the dog was found in 1924 by Sherring- 

 ton (181) to abolish thermoregulatory responses in 

 the body region caudal to the transection level (fig. 8). 

 Chronic partial or total decortication (117, 158), or 

 even hemidecerebration (22), does not severely influ- 

 ence temperature regulation. The thalamus and the 

 corpus striatum are not essential for a normal tem- 

 perature regulation (21, 53, 147, 171), wiiich is 

 perhaps surprising since surface thermoreceptors prob- 

 ably project to the hypothalamus via thalamic relays 



(59)- 



In chronic experiments on cats and monkeys, 

 Ranson, Magoun and co-workers (52, 170, 171, 191) 

 showed that small lesions in the anterior hypothala- 

 mus (shown in fig. 9) reduce or aljolish the thermo- 

 regulatory response to body warming (heat-loss 

 mechanism), while lesions in the posterior hypothala- 

 mus also abolish the response to body cooling (both 

 heat-loss and heat-production mechanisms). 



FIG. 7. Parasagittal section through the preoptic area and 

 hypothalamus of the goat. Electrical stimulation in the cross- 

 hatched area produces polypnea, vasodilatation in ears and 

 inhibition of shivering in the unanesthetized animal. Applica- 

 tion of electrodes is by the Hess technique. Co., anterior com- 

 missure; Ch.o., optic chiasma; Cm., mammillary body; C.f.d., 

 column, fornic desc; and \ .d'A., Vicq d'Azyr's bundle. [From 

 Andersson (4).] 



