UNANESTHETIZED POIKILOTHERMIC DOG— KELLER 



77 



DOG NO. 391 



22 SEPT. 1955 



VOLS. 



; 7o 



18.0 



40.0 



28.0 



< o/ -s 16.0 — 



14.0 



2 3 



TIME-HOURS 



Fig. 14. — Serial whole blood pH, CO2 and arterial O, on cooling in a representative 



experiment. 



emotionally to being teased or stroked. The animals exhibit no outward signs of 

 discomfort from cold. 



Disturbance in movements of progression are not discernible until body core tem- 

 perature reaches the neighborhood of 34° C, at which point there is a suspicion of 

 a lack of smoothness in muscular movement. At 32° C. there is a definite slowness 

 in muscular movement with a beginning appearance of a characteristic "gait." At 

 30° C, superimposed upon the "gait" which is now definite, is an occasional stagger 

 to one side or the other with automatic "catching" of the body to prevent falling. 

 At 28° C. the immediately foregoing irregularities may or may not be noticeably 

 intensified. It is suspected that this variation at 28° C. in the severity of symptoms 

 from one animal to another is a function of the duration of core hypothermia. 



In general it is surprising that an animal is so little disturbed by a body tempera- 

 ture of 30 to 28° C. Analysis of the foregoing forces the conclusion that a 10° C. 

 reduction of body temperature below the homothermic level does not eliminate or 

 materially impair functions associated with cerebration, central and peripheral syn- 

 aptic conduction and the contractile process in muscle. The staggering and "catching" 

 of the body is interpreted as evidence of a beginning disturbance in the postural 

 reflexes, presumably at the central synapse. 



REFERENCES 



Ott, Issac: Tlie thermogenic center in tlie tuber cinereum. Med. P>ull. 17: 146, 1895. 

 Isenschmid, R., and Schnitzler, W. : Beitrag zur Lokalisation des der Warmeregulation 



vorstehenden Zentralapparates im Zwischenhirn, Arch. f. exper. Path. u. Pharmakol. 



76: 202-223, 1914. 



