NEURO-MUSCULAR ORGANIZATION OF SHIVERING 
DR. HENSEL: In the record, I saw that after administration of 
acetylcholine the blood pressure fell from about 120 to about 60; and 
I wonder whether there isany possibility that the blood supply of the 
brain mi^t have changed. We know that shivering is very much in- 
fluenced by changes in oxygen pressure and CO pressure. Might 
this not be the cause of your change 7 1 do not know, but how did you 
exclude this possibility? 
DR. STUART: To say that the particular activating system is 
adrenegic and that it would be facilitated by an injection of epineph- 
rine and inhibited by acetylcholine, is a point of great controversy 
today, I think, among neuropharmacologists. I did notthink that Dr. 
Kawamura meant to imply that this was necessarily so; but he is 
suggesting that this is one alternative. 
DR. CLARK: That difference in shivering intensity between sum- 
mer and winter is intriguing. Did you, by any chance, give any of 
your winter-summer dogs thyroxin? 
DR. KAWAMURA: No, I have never applied thyroxin to the dogs 
in this experiment. 
DR. CLARK: And was the difference between summer and winter 
shivering only observed under sodium amytal anesthesia as well? 
DR . KAWAMURA: Yes, I tried anesthesia with other barbiturates 
too. Pentobarbital, thiopental, and ether were used. The summer- 
winter differences in shivering were the same, independent of the 
anesthetic drug. Sometimes I could induce weak shivering even in 
summer in the dog, but it was very difficult to get and was short 
lasting. 
DR. CLARK: I operate under nembutal and routinely I see my 
animals shivering when they are coming out of the anesthesia re- 
gardless of the season. 
DR. JOHANSEN: In regard to the interrelations you have pro- 
posed between respiration and shivering, have you ever tried to 
manipulate with the respiratory phases in an anesthetized animal? 
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