AJP - Regulatory, Integrative and Comparative Physiology, Vol 246, Issue 2 242-R246, Copyright © 1984 by American Physiological Society

ARTICLES

Circadian brain and body temperature rhythms in the squirrel monkey

C. A. Fuller

This study examines the hypothalamic temperature rhythm and its relationship with the colonic temperature rhythm of squirrel monkeys in 24-h light-dark cycles (LD 12:12) at four different ambient temperatures (Ta). The waveforms and phases of both temperature rhythms were similar in all TaS. The rhythm amplitudes were, however, reduced as Ta increased. The 24-h means also showed systematic decreases at higher TaS. The hypothalamic temperature was regulated over a narrower range than the colonic temperature and was higher than colonic temperature at all TaS except the warmest. Further, the mean nighttime temperatures were influenced more by Ta than were the mean daytime temperatures. In summary, the hypothalamic and colonic temperature rhythms are very similar in their circadian regulation. However, the mean temperature levels of these rhythms are controlled differentially. Thus these rhythms are the integrated response of both the circadian and thermoregulatory control systems.

This article has been cited by other articles:

				S. K. Maloney, D. Mitchell, G. Mitchell, and A. Fuller Absence of selective brain cooling in unrestrained baboons exposed to heat Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2007; 292(5): R2059 - R2067. [Abstract] [Full Text] [PDF]