HENSEL, H. 
generally accepted than the effects during cooling, as you know. 
DR. FREEMAN: You never over-cool? 
DR. HENSEL: No. 
DR. HEMINGWAY: You say you use a one-millimeter thermode 
and put that in the hypothalamus five times without damage? 
DR. HENSEL: I would say, without any visible change in the 
cat's behavior. 
DR. HEMINGWAY: Because the anterior hypothalamic region is 
not very many millimeters in extent. 
DR. HENSEL: Of course, in other cats, we made a histological 
investigation of this region, but not in the cat where the implantation 
was made several times. This cat is still living. 
DR. FREEMAN: That is humane, of course! 
DR. HENSEL: But in the other cats where the implantation 
was made for only one time, there was very little damage and very 
little reaction. 
DR. FREEMAN: How far laterally to the midline are these 
inserted? 
DR. HENSEL: Three or four millimeters. 
DR. FREEMAN: Any closer than that, we found that you either 
lacerate the choroid plexuses or you may obstruct the pyramidal 
row. 
DR. STUART: Was this the same in the posterior hypothalamus, 
three or four millimeters from the midline? 
DR. HENSEL: Yes, we tried various distances, but we did not 
see an effect as yet, nor with the vasomotor response. 
76 
