A. Mailloux et al., Body temperature and locomotor activity as marker rhythms of aging of the circadian system in rodents, EXP GERONT, 34(6), 1999, pp. 733-740
Most biological functions present rhythmic variations. These rhythms are di
stinguished by their period and concern all the levels of biological life.
Circadian rhythms follow a periodicity close to 24-h, they allow individual
s to survive via adaptation to the periodic variations of environment. Thro
ughout the aging process, modifications in circadian rhythms of endocrinolo
gical, metabolical and behavioural fields have been found in many animal sp
ecies. This review updates the body of knowledge on aging-related alteratio
ns of the circadian rhythms of body temperature and locomotor activity: mod
ifications in circadian profiles, modifications in the period of free-runni
ng rhythms, internal desynchronisations and modifications in entrainment ab
ility of these rhythms. (C) 1999 Elsevier Science Inc. All rights reserved.