Entrainment and coupling of the hamster suprachiasmatic clock by daily dark pulses
Autor: | Jorge E. Mendoza, Etienne Challet, Paul Pévet |
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Přispěvatelé: | Institut des Neurosciences Cellulaires et Intégratives (INCI), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS) |
Rok vydání: | 2009 |
Předmět: |
Male
Calbindins medicine.medical_specialty [SDV]Life Sciences [q-bio] Circadian clock Cell Count Motor Activity Biology 03 medical and health sciences Cellular and Molecular Neuroscience S100 Calcium Binding Protein G 0302 clinical medicine Biological Clocks Cricetinae Internal medicine medicine Animals CLOCK Proteins Circadian rhythm Extracellular Signal-Regulated MAP Kinases ComputingMilieux_MISCELLANEOUS 030304 developmental biology Analysis of Variance 0303 health sciences Mesocricetus Suprachiasmatic nucleus Intracellular Signaling Peptides and Proteins Period Circadian Proteins Darkness Immunohistochemistry Circadian Rhythm CLOCK Endocrinology Light effects on circadian rhythm Biophysics Suprachiasmatic Nucleus sense organs Entrainment (chronobiology) Proto-Oncogene Proteins c-fos 030217 neurology & neurosurgery |
Zdroj: | Journal of Neuroscience Research Journal of Neuroscience Research, Wiley, 2009, 87 (3), pp.758-765. ⟨10.1002/jnr.21887⟩ |
ISSN: | 1097-4547 0360-4012 |
Popis: | The circadian rhythm of locomotor activity of hamsters kept in constant light (LL) can split into two distinct components that, in steady state, lie 180 degrees apart. The splitting phenomenon is the result of antiphase circadian oscillations between left and right sides of the suprachiasmatic nuclei (SCN), the master circadian clock in mammals. In unsplit hamsters housed in LL, a single dark pulse produces a phase-shift of the wheel-running activity rhythm, accompanied by a transient down-regulation of clock gene expression in the SCN. In the present study, we evaluated the effects of daily 1-hr dark pulses on wheel-running activity rhythm and on the expression of clock and nonclock proteins in the SCN of Syrian hamsters exposed to LL conditions. The results show that a daily 1-hr dark pulse entrained the rhythm of wheel-running activity of unsplit hamsters. In addition, in split animals, unimodal coupling of the two locomotor activity components was produced by daily 1-hr dark pulses. In the SCN, the effects of entrainment and unimodal coupling of the two separate components by dark observed in behavior were also evident in the bilateral expression of the proteins c-FOS, p-ERK, PERIOD 1, and calbindin. These results show that the bilaterally asymmetric SCN clock, underlying split circadian behavior, can be recoupled in phase and entrained by short daily dark exposure, indicating the synchronizing potency of darkness on the main circadian clock. |
Databáze: | OpenAIRE |
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