ROLE OF THE PROSENCEPHALON IN SHIVERING 
and bulb. Although the production of tremulous activity probably 
involves a reticular formation activation from a more rostral 
structure than the midbrain (Carpenter, 1958), it is conceivable 
that in the decerebrate animal, there could be a nocioceptive stim- 
ulation of reticular neurons capable of producing tremor. This 
suggestion awaits experimental confirmation. 
The results listed in Table I confirm the work of Dusser de 
Barenne (1920), Bazett and Penfield (1922), Bazett, Alpers, and 
Erb (1933), Keller (1959), and Bard and Macht (1958). Bard and 
Macht kept animals alive for many months after decerebration and 
reported that several weeks after surgery there was a return of 
cold-induced fine rapid tremors in decerebrate cats that resembled 
shivering. However, in a later report, Bard (1961) stated that al- 
thou^ such cold- induced muscular activity increased in frequency 
and vigor during extreme falls in environmental and body tempera- 
ture, it did not affect the rate of body temperature decline. It would 
seem that Bard and Macht 's results support the above-mentioned 
concept of shivering being replaced after decerebration by somatic 
activity alternatively and intermittently rhythmic and arrhythmic 
and deficient in heat productive capacity. 
Unfortunately, all the above work refutes, yet cannot explain, 
Dworkin's (1930) report of shivering returning in chilled rabbits 
from 5 to 230 minutes after brainstem transection as low as the 
caudal pons. Moreover, the body temperatures of these preparations 
rose while "shivering." Barbour (1939) reported the return of shiv- 
ering in two cats one and two days after decerebration, but his 
account seems too fragmentary to support Dworkin and refute all 
previous and subsequent work. Although the majority of past and 
present evidence supports the concept of shivering production in- 
volving a more rostral neural structure than the midbrain, there is 
no satisfactory explanation in the literature of Dworkin's diverse 
results. However, on the basis of the metabolic data presented and 
the observations of Bard and Macht on animals more carefully 
nursed for longer periods oftime after surgery, the evidence seems 
to favour a lack of true shivering in decerebrate preparations. 
305 
