Aging of the Mammalian Circadian System

TUREK, F.W., SCARBROUGH, K., PENEV, P., LABYAK, S., VALENTINUZZI, V.S. AND VAN REETH, O

Handbook of Behavioral Neurobiology

Kluwer Academic/Plenum Publishers

Lugar: New York; Año: 2000; p. 292 - 317

Numerous studies have demonstrated that as animals reach advanced age for the species, there are pronounced changes in the expression of diverse circadian rhythms. Many of the observed changes may reflect an overall deterioration of the health of the organism. On the other hand, changes in the circadian system may not simply reflect such deterioration, but may represent one of the underlying causes for the negative health effects associated with advanced age. Most studies of the effects of advanced age of the circadian system have been carried out on rodents and humans. This chapter will focus primary on studies of rodents, particularly the best-studied animals in this regard: laboratory rats, mice and golden (Syrian) hamsters. After first describing the multitud of changes that have been observed in the aging circadian system of rodents, this review will (1) examine the underlying physiological mechanisms that lead to these changes, (2) provide an overview of attempts to attenuate or reverse age-related effects on circadian rhythmicity, and (3) speculate on the functional significance of such changes.