Special Issue: Circadian Rhythms and Age Related Disorder: How Does Aging Impact Mammalian Circadian Organization?

Abstract

Aging significantly impacts circadian timing in mammals. The amplitude and precision of behavioral, endocrine, and metabolic rhythms decline with age. This is accompanied with an age‐related decline in the amplitude of central pacemaker output, although the molecular clock in the suprachiasmatic nucleus exhibit robust oscillation. Peripheral clocks also exhibit robust oscillation during aging, when extensive reprogramming of other genes’ expression rhythms occurs in peripheral tissues. The age‐related dissociation between the molecular clock and downstream rhythms in both central and peripheral tissues indicates that mechanisms other than the molecular clock are involved in mediating the impact the aging on circadian organization. In this article, findings are reviewed on the impact of aging on circadian timing functions, and the potential role of increased inflammatory response in age‐related changes in circadian organization is highlighted.

Dim Light at Night Promotes Circadian Disruption in Female Rats, at the Metabolic, Reproductive, and Behavioral Level

“…[92] These studies were performed in male rodents; there is only one study reporting the effects of DLAN in the response of the immune system in aged females mice, and in this study an impaired inflammatory response was observed. [93] As circadian rhythms change during lifespan [94][95][96] and it has been previously reported that circadian challenges affects differentially young and aged rodents, [97] DLAN exposure might induce a different outcome in this population not only at the level of the immune system but also in other physiological processes.…”

The interplay between sleep and ecophysiology, behaviour and responses to environmental change in fish

“…This alludes to one function of sleep: it can be considered as a means of slowing some cellular processes to conserve energy. Similarly, across taxa, the endogenous circadian clock becomes impaired with age ( Xu and Li, 2022 ; Zhao et al, 2019 ). This is observed in Nothobranchius korthausae , whereby senescent fish do not maintain their endogenous rhythm in the absence of a light zeitgeber ( Lucas-Sánchez et al, 2013 ).…”

Different levels of circadian (de)synchrony ­– where does it hurt?

“…Ageing leads to downhill changes in physiology and body homeostasis gradually weakening the circadian system. And in turn a weakened circadian system promotes the age-related morbidities (reviewed in Duffy et al , 2015 ; Verma et al , 2023 ; Xu & Li, 2022 ). Studies are therefore, in demand to test and state the cause-and-effect relationship between the disease and the risk factors.…”