LIM, T. P. K. 
DISCUSSION 
DR. HENSEL: May I make a general suggestion not to use 
the word "receptor" for the central mechanism. I think it is better 
to use "receptor" only for a defined mechanism. Of course, the 
central mechanism can be sensitive to temperature. It can be 
changed in the activity of some neural unit, but it must not be a 
receptor in the sense of receptor. 
DR. LIM: Not in the anatomical sense. 
DR. HENSEL; May I ask another question? I think it is very 
important to discriminate between the natural conditions and the 
artificial conditions in the experiments because if you cool an 
animal from outside, under natural conditions, you would get at 
the same time an increase in hypothalamic temperature. I think 
under natural conditions it very seldom occurs that hypothalamic 
temperature actually drops during external cooling. The drop in 
hypothalamic temperature can be brought about by artificial cooling, 
of course, but it does not occur when cooling a cat in a cold 
chamber. 
DR. LIM: Yes, we knew this. That was the one reason we added 
this rather artificial situation. The main purpose was to dissociate 
two areas, by means of which we can maintain amy level of steady 
state. 
DR. HENSEL: Yes, of course, the discrimination of the mechan- 
ism is very important. 
DR. CLARK: May I also make a comment: First of all, I think 
in allprobability your conclusions are fine. lam not willing to accept 
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