ROLE OF THE PROSENCEPHALON IN SHIVERING 
and Erb (1933), would indicate that structures more rostral than the 
posterior hypothalamus could play but a secondary role in the 
production of shivering. 
The data listed in Figure 13 and those later to be discussed in 
Figure 21 indicate that the ventrolateral midseptum is facilitating 
and the ventromedial midseptum inhibitorywith respect to shivering. 
Jacobson, Craig and Squires (19 60) found that electrolytic destruction 
of the ventromedial midseptum suppresses the shivering of lightly 
anesthetized cats. This implied that the ventromedial midseptum 
was involved in the production of shivering, and as such conflicts 
with our concept. An experiment was then performed to illustrate 
that the results from the two laboratories do not conflict, only the 
interpretation. In this experiment, shown in Figure 15, bipolar 
electrodes were inserted bilaterally into the center of the lesion 
shown in the top lefthand corner of Figvire 13, i.e., the photograph 
of a frontal section through the septal region. The tracts of the 
electrode do not appear because the brain was sectioned at a dif- 
ferent angle to the paths of the electrode tracts. When these elec- 
trodes were inserted, the brain was intact; the lesions were produced 
later in the experiment. A bipolar electrode was also inserted into 
the posterior hypothalamus as indicated by the white stain in the 
lower photograph. The locus stimulated by this electrode was the 
lowermost tip of the white stain. (Unfortunately this electrode 
slipped medially several days after the experiment when it was 
being removed from the living cat. Hence the white stain shows a 
vertical and a slanted angle to the electrode tract.) This cat was 
anesthetized with pentobarbital sodium (35 mg/kg I. P.), and once 
spontaneous shivering began, the following sequence of stimuli was 
applied, as shown in the figure in which the upper record is the 
electromyogram of the forelimb and the lower record the duration 
of the stimulus: 
1. 16 OOa^ A/pulse stimulation of the righ ventromedial mid- 
septum to suppress shivering for the 30- second duration of stimulus. 
2. 800)Li A/pulse stimulation of the posterior hypothalamus to 
augment shivering for the 30-second duration of stimulus. 
3. Right ventromedial midseptum destruction by cathodal 
351 
