ROLE OF THE PROSENCEPHALON IN SHIVERING 
in response to nocioceptive stimuli. The resting and shivering oxy- 
gen consumption rates 28 and 570 days after surgery were similar 
to those measurements made before decortication. Continuous 
shivering in response to cooling was observed. 
The resting and shivering oxygen consumption rates of the one 
hemidecorticate animal tested 42 days after surgery lay within the 
normal range, although great difficulty was experienced inmeasuring 
resting VO . This animal with a left-side decortication continually 
circled to the left after surgery and tended to be hyperactive. 
Shivering appeared to be of equal intensity and duration on both 
sides of the body. 
The range in bocfy wei^t of the animals three days after sur- 
gery was from 8 to 15 per cent of the weights before surgery. As 
shown in Table IV, the range in body weight of three intact cats 
after a three-day fast was from 6 to 15 percent that of before-fast 
weights. However, these three cats shivered just as effectively after 
as before fasting. 
All animals, during all tests before and after decortication and 
fasting, assumed a huddled posture while shivering. 
Comments . These results would suggest that in a chronic de- 
corticate cat the intensity of shivering is normal, but in the acutely 
decorticate stage, shivering is diminished in intensity even though 
such a preparation is displaying overt visceral activity symptomatic 
of hyperactive hypothalamic function. This conflicts with Bard's 
(1961), Pinkston, Bard, and Rioch's (1934), andAring's (1935) ob- 
servations of cold-induced shivering appearing with more vigor and 
shorter latency after decortication. My chronic observations in- 
volve but one cat, whereas the above investigators studied more cats 
for longer periods of time after surgery. On the other hand, they do 
not have the support of metabolic data similar'to that presented in 
Table II. If Pinkston, Bard, and Rioch's observations of a tendency 
to chronic peripheral vasodilatation after decortication is valid, 
it is conceivable that after decortication, shivering would appear 
with less latency on exposure to cold since the blood temperature 
should drop more rapidly. Conversely, if shivering is instigated 
more by a change in skin rather than blood temperature (as sug- 
gested first by Liebermeister in 1860, and more recently by 
311 
