ROLE OF THE PROSENCEPHALON IN SHIVERING 
o 
temperatures maintained near 38 C. The body temperatures were 
then lowered 0.5 C to 9 C by immersing the cats in cool water 
for 10 minutes. Ten minutes after completion of this cooling stress 
the oxygen consumption rates (VO ) were redetermined over a 20- 
minute period. During the cooling stress and second determination 
of VO , the somatic responses of each animal were checked by in- 
dependent observation. Somatic responses included all forms of 
skeletal muscular activity and patterns of movement that were 
apparent on visual inspection. By independent observation it is 
meant that more than one investigator visually inspected each 
preparation and after such inspection the somatic responses were 
discussed. 
Comparisons were made of the somatic responses during such 
rapid cooling and during slower cooling (exposure to 2 5 C environ- 
mental temperature), rapid rewarming (immersion in 50 C water) 
and slower rewarming (immersion in 40 C water). After these 
tests an attempt was made to keep the animals alive for further tests 
at one month post surgery, but this met with failure. Of the 22 cats 
decerebrate surgery was performed on, 20 lived one day or more, 
13 two days or more, 9 three days or more and five 5 days or more 
post surgery. 
After these tests the animals were sacrificed and their brains 
fixed in formalin for gross and sometimes histological inspection. 
Results 
Somatic observations. Table I summarizes the metabolic and 
somatic responses of seven decerebrate cats subjected to a rapid 
cooling test one to nine days after surgery. All the animals made 
somatic responses to the rapid cooling stress of immersion in cold 
water. Movements consisted of intermittent spasmodic twitches, 
jerks and large amplitude kicks and running movements of the 
somatic musculature. These somatic responses were accompanied 
by an increase in respiratory rate and depth. The violence and fre- 
quency of these intermittent movements were greater in the animals 
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