The Circadian Timing system: Making Sense of day/night gene expression
Biol. Res
;
37(1): 11-28, 2004. ilus, graf
Article
Dans Anglais
| LILACS
| ID: lil-365976
RESUMO
The circadian time-keeping system ensures predictive adaptation of individuals to the reproducible 24-h day/night alternations of our planet by generating the 24-h (circadian) rhythms found in hormone release and cardiovascular, biophysical and behavioral functions, and others. In mammals, the master clock resides in the suprachiasmatic nucleus (SCN) of the hypothalamus. The molecular events determining the functional oscillation of the SCN neurons with a period of 24-h involve recurrent expression of several clock proteins that interact in complex transcription/translation feedback loops. In mammals, a glutamatergic monosynaptic pathway originating from the retina regulaltes the clock gene expression pattern in the SCN neurons, synchronizing them to the lightdark cycle. The emerging concept is that neural/humoral output signals from the SCN impinge upon peripheral clocks located in other areas of the brain, heart, lung, gastrointestinal tract, liver, kidney, fibroblasts, and most of the cell phenotypes, resulting in overt circadian rhythms in integrated physiological functions. Here we review the impact of day/night alternation on integrated physiology; the molecular mechanisms and input/output signaling pathways involved in SCN circadian function; the current concept of peripheral clocks; and the potential role of melatonin as a circadian neuroendocrine transducer.
Texte intégral:
Disponible
Indice:
LILAS (Amériques)
Sujet Principal:
Noyau suprachiasmatique
/
Expression des gènes
/
Rythme circadien
/
Mélatonine
Limites du sujet:
Animaux
langue:
Anglais
Texte intégral:
Biol. Res
Thème du journal:
Biologie
Année:
2004
Type:
Article
Pays d'affiliation:
Chili
Institution/Pays d'affiliation:
Pontificia Universidad Catolica de Chile/CL
/
Universidad Austral de Chile/CL
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