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Titolo:
Artificially accelerated aging by shortened photoperiod alters early gene expression (Fos) in the suprachiasmatic nucleus and sulfatoxymelatonin excretion in a small primate, Microcebus murinus
Autore:
Aujard, F; Dkhissi-Benyahya, O; Fournier, I; Claustrat, B; Schilling, A; Cooper, HM; Perret, M;
Indirizzi:
CNRS, Lab Ecol Gen, UMR 8571, F-91800 Brunoy, France CNRS Brunoy France F-91800 ab Ecol Gen, UMR 8571, F-91800 Brunoy, France INSERM, U371, F-69675 Bron, France INSERM Bron France F-69675INSERM, U371, F-69675 Bron, France Hop Neurocardiol, Ctr Med Nucl, Serv Radiopharm & Radioanal, F-69334 Lyon,France Hop Neurocardiol Lyon France F-69334 rm & Radioanal, F-69334 Lyon,France
Titolo Testata:
NEUROSCIENCE
fascicolo: 2, volume: 105, anno: 2001,
pagine: 403 - 412
SICI:
0306-4522(2001)105:2<403:AAABSP>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
MALE PROSIMIAN PRIMATE; LESSER MOUSE LEMUR; PLASMA MELATONIN; CIRCADIAN SYSTEM; OLD HAMSTERS; AGED RATS; LIGHT; RHYTHMS; SLEEP; MICE;
Keywords:
aging process; circadian rhythms; biological clock; light response; melatonin; Microcebus murinus;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
50
Recensione:
Indirizzi per estratti:
Indirizzo: Perret, M CNRS, Lab Ecol Gen, UMR 8571, 4 Ave Petit Chateau, F-91800 Brunoy, France CNRS 4 Ave Petit Chateau Brunoy France F-91800 0 Brunoy, France
Citazione:
F. Aujard et al., "Artificially accelerated aging by shortened photoperiod alters early gene expression (Fos) in the suprachiasmatic nucleus and sulfatoxymelatonin excretion in a small primate, Microcebus murinus", NEUROSCIENC, 105(2), 2001, pp. 403-412

Abstract

In mammals, a number of anatomical and functional changes occur in the circadian timing system with aging. In certain species, aging can be modified by various factors which induce a number of pathological changes. In a small primate, the gray mouse lemur (Microcebus murinus), long-term acceleration of seasonal rhythms by exposing the animals to a shortened photoperiodic regime (up to 2.5 times the natural photoperiodic regime) alters longevity,based on survival curves and morphological changes. This provides a model for challenging the idea that modifications of the circadian pacemaker are related to chronological (years) versus biological (photoperiodic cycles) age. To assess the effect of aging and accelerated aging on the circadian pacemaker of this primate, we measured body weight variations, the daily rhythm in urine 6-sulfatoxymelatonin and the light-induced expression of the immediate early gene (Fos) in the suprachiasmatic nucleus of mouse iemurs that had been exposed to different photoperiodic cycles. Urine samples were collected throughout the day and urine 6-sulfatoxymelatonin levels were measuredby radioimmunoassay. Light-induced Fos expression in the suprachiasmatic nucleus was studied by exposing the animals to a 15-min monochromatic pulse of light (500 nm) at saturating or sub-saturating levels of irradiance (10(11) or 10(14) photons/cm(2)/s) during the dark phase. The classical patternof 6-sulfatoxymelatonin excretion was significantly altered in aged mouse lemurs which failed to show a nocturnal peak. Fos expression following exposure to low levels of irradiance was reduced by 88% in the suprachiasmatic nucleus of aged mouse lemurs, Exposure to higher irradiance levels showed similar results, with a reduction of 66% in Fos expression in the aged animals, Animals subjected to artificially accelerated aging demonstrated the same alterations in melatonin production and Fos response to light as animalsthat had been maintained in a routine photoperiodic cycle. Our data indicate that there are dramatic changes in melatonin production and in the cellular response to photic input in the suprachiasmatic nucleusof aged mouse lemurs, and that these alterations depend on the number of expressed seasonal cycles rather than on a fixed chronological age. These results provide new insights into the mechanisms underlying artificial accelerated aging at the level of the molecular mechanisms of the biological clock. (C) 2001 IBRO. Published by Elsevier Science Ltd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 30/03/20 alle ore 13:22:25