Journal ArticleDOI
Circadian profile of Per gene mRNA expression in the suprachiasmatic nucleus, paraventricular nucleus, and pineal body of aged rats
Makoto Asai,Yuko Yoshinobu,Kaneko Satoshi,Akiko Mori,Takato Nikaido,Takahiro Moriya,Masashi Akiyama,Shigenobu Shibata +7 more
TLDR
The present results suggest that the molecular mechanism of clock oscillation in theSCN, PVN, and pineal body is preserved against aging, whereas the impairment of Per1 induction in the SCN after light stimulation may result in impaired behavioral photic entrainment in aged rats.Abstract:
Aging alters circadian components such as the free-running period, the day-to-night activity ratio and photic entrainment in behavioral rhythms, and 2-deoxyglucose uptakes and neuronal firing in the suprachiasmatic nucleus (SCN). A core clock mechanism in the mouse SCN appears to involve a transcriptional feedback loop in which Period (Per) and Cryptochrome (Cry) genes play a role in negative feedback. The circadian rhythm systems include photic entrainment, clock oscillation, and outputs of clock information such as melatonin production. In this experiment, we examined clock gene expression to determine whether circadian input, oscillation, and output are disrupted with aging. Circadian expression profiles of rPer1, rPer2, or rCry1 mRNA were very similar in the SCN, the paraventricular nucleus of the hypothalamus (PVN), and the pineal body of young and aged (22-26 months) rats. On the other hand, the photic stimulation-induced rapid expression of Per1 and Per2 in the SCN was reduced with aging. The present results suggest that the molecular mechanism of clock oscillation in the SCN, PVN, and pineal body is preserved against aging, whereas the impairment of Per1 induction in the SCN after light stimulation may result in impaired behavioral photic entrainment in aged rats.read more
Citations
More filters
Journal ArticleDOI
The circadian clock and pathology of the ageing brain
TL;DR: New data from experiments in model organisms, gene expression studies and clinical trials imply that dysfunctions of the circadian clock contribute to ageing and age-associated pathologies, thereby suggesting a functional link between the circadian Clock andAge-associated decline of brain functions.
Journal ArticleDOI
Circadian activity rhythms and risk of incident dementia and mild cognitive impairment in older women
Gregory J. Tranah,Terri Blackwell,Katie L. Stone,Sonia Ancoli-Israel,Misti L. Paudel,Kristine E. Ensrud,Jane A. Cauley,Susan Redline,Teresa A. Hillier,Steven R. Cummings,Kristine Yaffe +10 more
TL;DR: It is determined whether circadian activity rhythms measured in community‐dwelling older women are prospectively associated with incident dementia or mild cognitive impairment (MCI).
Journal ArticleDOI
Challenging the omnipotence of the suprachiasmatic timekeeper: are circadian oscillators present throughout the mammalian brain?
Clare Guilding,Hugh D. Piggins +1 more
TL;DR: This review examines the evidence for extra‐SCN circadian oscillators in the mammalian brain and highlights some of the essential properties and key differences between brain oscillators.
Journal ArticleDOI
Age-Related Decline in Circadian Output
Takahiro Nakamura,Wataru Nakamura,Shin Yamazaki,Takashi Kudo,Tamara Cutler,Christopher S. Colwell,Gene D. Block +6 more
TL;DR: The circadian output measured at the level of neural activity rhythms in the SCN is degraded by aging, and this decline occurs before the disruption of key components of the molecular clockwork.
Journal ArticleDOI
The aging clock: circadian rhythms and later life
Suzanne Hood,Shimon Amir +1 more
TL;DR: Key findings from the study of circadian rhythms in later life are synthesized, patterns of change documented to date are identified, and potential physiological mechanisms that may underlie these changes are reviewed.
References
More filters
Journal ArticleDOI
Molecular Bases for Circadian Clocks
TL;DR: It used to be that research in chronobiology moved biochemical functions [transcriptional activators], the along at a gentlemanly pace, but by mid 1997 the word in determining what the authors perceive as time was PASWCCLK.
Journal ArticleDOI
mCRY1 and mCRY2 are essential components of the negative limb of the circadian clock feedback loop.
Kazuhiko Kume,Mark J. Zylka,Sathyanarayanan Sriram,Lauren P. Shearman,David R. Weaver,Xiaowei Jin,Elizabeth S. Maywood,Michael H. Hastings,Steven M. Reppert +8 more
TL;DR: It is determined that two mouse cryptochrome genes, mCry1 and mCry2, act in the negative limb of the clock feedback loop, and the mPER and mCRY proteins appear to inhibit the transcriptional complex differentially.
Journal ArticleDOI
A molecular mechanism regulating rhythmic output from the suprachiasmatic circadian clock.
Xiaowei Jin,Lauren P. Shearman,David R. Weaver,Mark J. Zylka,Geert J. De Vries,Steven M. Reppert +5 more
TL;DR: Luciferase reporter gene assays indicate that the transcriptional machinery of the core clockwork directly regulates a clock-controlled output rhythm.
Journal ArticleDOI
A differential response of two putative mammalian circadian regulators, mper1 and mper2, to light.
TL;DR: It appears that mper1 is the pacemaker component which responds to light and thus mediates photic entrainment in Drosophila period and mper2.
Journal ArticleDOI
Three period homologs in mammals : differential light responses in the suprachiasmatic circadian clock and oscillating transcripts outside of brain
TL;DR: The mouse cDNA of a third mammalian homolog of the Drosophila period gene is cloned and characterized, highlighting the differential light responses among the three mammalian Per genes in the SCN and raising the possibility of circadian oscillators in mammals outside of brain and retina.