title: Extracellular nitric oxide signaling in the hamster biological clock.
abstract: Nocturnal light pulses induce phase shifts in circadian rhythms and activate cFos expression in the suprachiasmatic nuclei (SCN). We have studied the role of nitric oxide (NO) in the intercellular communication within the dorsal and ventral portions of the SCN in Syrian hamsters. Administration of the NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide blocked photic phase advances in a dose-dependent manner and inhibited light-induced cFos-ir, without affecting light-induced circadian phase delays. These results suggest that NO may act as an intercellular messenger in the SCN, mediating light-induced phase advances.
authors.affiliation: Laboratorio de Cronobiología, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque Saenz Peña 352, Bernal B1876BXD, Buenos Aires, Argentina.
authors.forename: Santiago A
authors.initials: SA
authors.lastname: Plano
authors.forename: Patricia V
authors.initials: PV
authors.lastname: Agostino
authors.forename: Diego A
authors.initials: DA
authors.lastname: Golombek
mesh_terms: D000818:Animals; D001683:Biological Clocks / Q000502:physiology*; D006224:Cricetinae; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D009569:Nitric Oxide