Effect of neonatal decerebration on thermogenesis during starvation and cold exposure in the rat

Decerebration activates thermogenesis in the rat.

“…The initial experiment, on adult rats allowed to recover after suction decerebration, supports the findings of Bignall et al (1975) in neonatal rats. Decerebration, carried out at the immediate pre-pontine level under direct vision, produced a large and sustained rise in rectal temperature which did not appear to be associated with increased physical activity immediately after the operation.…”

“…in animals with ventromedial hypothalamic lesions (Han, 1967;Goldman, Bernardis & Frohman, 1974), also implicate this area in the control of thermogenesis. In contrast, Bignall, Heggenness & Palmer (1975) have reported that temperature regulation is only partially impaired in neonatal rats after surgical removal of the hypothalamus. This group has also shown that decerebration of neonatal rats produces maximal thermogenesis and a large increase in rectal temperature, both of which are unaffected by fasting or by high ambient temperature.…”

“…These findings suggest that thermogenesis is normally controlled by descending inhibition of centres, probably located in the brain stem, which in turn control heat generating systems. Bignall et al (1975) assumed that the increased heat production following decerebration was due to brown adipose tissue thermogenesis, but this assumption was not tested and studies were not performed on adult animals because the authors claimed that changes in muscle tension and hyperactivity followed decerebration.…”

Impaired Suppression of Sympathetic Activity during Fasting in the Gold Thioglucose-treated Mouse

“…Malnourished human infants and acutely starved, preweanling rats fail to increase oxygen consumption normally upon exposure to environmental temperatures of 20°-30°C (29,30). In rats, this metabolic restraint of fasting is eliminated by surgical decerebration, indicating the presence of descending inhibitory input in these fasting animals (31). Because the role of sympathetic activation in promoting heat production (oxygen consumption) in the defense against environmental cold is well recognized (32), such data in fasted, coldexposed rats are consistent with the model shown in Fig.…”

“…The plastic-coated thermistor was dipped in mineral oil and inserted 2 cm into the (30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40) Ci/mmol sp act; New England Nuclear, Boston, Mass.) was purified before use by column chromatography with alumina as described below.…”