I 
ROLE OF THE PROSENCEPHALON IN SHIVERING 
polarization of the electrode to suppress shivering for the 90- second 
duration of stimulus. 
3 . (Not shown). The same destruction on the left side to 
produce a lesion the extent of which is shown in the upper photo- 
graph of Figure 15 and which suppressed shivering completely. 
4. Reproduction of shivering by 1600 /i A/pulse stimulation of 
the posterior hypothalamus for the 60- second duration of stimulus. 
•The above stimuli were applied to the animal in the anesthetized 
state. After bilateral ventromedial midseptal destruction the animal 
only shivered when the posterior hypothalamus was electrically 
stimulated. However, four days later, in the unanesthetized state, 
the animal shivered vigorously on exposure to cold, the ratio of 
VO shivering/resting being 3.7. 
This experiment illustrates the suppression of shivering during 
stimulation of the ventromedial midseptum and during electrolytic 
destruction of the same region. Since shivering returned four days 
after surgery, it suggests that the immediate suppressive effects 
of electrolytic destruction of this region in the anesthetized cat 
masked the real role of this region in shivering, which is sup- 
pression. 
Unanesthetized Preparation Studies 
Methods. In six cats, electrodes were stereotaxically implanted 
in central nervous tissue sites permitting observation and recording 
of animal responses to either hypothalamic or septal electrical 
stimulation, in the unanesthetized and unrestrained state. 
Each preparation was first anesthetized (pentobarbital sodium, 
35 mg/kg), its head mounted in the stereotaxic frame, scalp skin 
incised and reflected, temporal muscles retracted, and calvarium 
exposed. Bipolar stimulating electrodes similar to those already 
described were stereotaxically placed at various subcortical sites 
by drilling appropriate holes in the calvarium. The electrodes were 
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