title: Nerve growth factor-induced circadian phase shifts and MAP kinase activation in the hamster suprachiasmatic nuclei.
abstract: Circadian rhythms are entrained by light and by several neurochemical stimuli. In hamsters housed in constant darkness, i.c.v. administration of nerve growth factor (NGF) at various times in their circadian cycle produced phase shifts of locomotor activity rhythms that were similar in direction and circadian timing to those produced by brief pulses of light. Moreover, the effect of NGF and light were not additive, indicating signalling points in common. These points include the immediate-early gene c-fos and ERK1/2, a component of the mitogen-activated protein kinases (MAPK) family. NGF activates c-FOS and ERK1/2-MAPK in the suprachiasmatic nuclei, the site of a circadian clock in mammals, when administered during the subjective night but not during the day. The effect of NGF on ERK1/2 activation was not inhibited by the administration of MK-801, a glutamate/NMDA receptor antagonist. These results suggest that NGF, acting through MAPK activation, plays a role in photic entrainment of the mammalian circadian clock.
authors.affiliation: Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, R.S. Peña 180, (1876) Bernal, Buenos Aires, Argentina.
authors.forename: Gastón A
authors.initials: GA
authors.lastname: Pizzio
authors.forename: Ernesto C
authors.initials: EC
authors.lastname: Hainich
authors.forename: Santiago A
authors.initials: SA
authors.lastname: Plano
authors.forename: Martin R
authors.initials: MR
authors.lastname: Ralph
authors.forename: Diego A
authors.initials: DA
authors.lastname: Golombek
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D015153:Blotting, Western / Q000379:methods; D002452:Cell Count / Q000379:methods; D002940:Circadian Rhythm / Q000187:drug effects*; D006224:Cricetinae; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004347:Drug Interactions; D004789:Enzyme Activation / Q000187:drug effects; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D007150:Immunohistochemistry / Q000379:methods; D008027:Light; D008297:Male; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009043:Motor Activity / Q000187:drug effects; D020932:Nerve Growth Factor / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D013493:Suprachiasmatic Nucleus / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors
chemical_list: D018691:Excitatory Amino Acid Antagonists; D016760:Proto-Oncogene Proteins c-fos; D016291:Dizocilpine Maleate; D020932:Nerve Growth Factor; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases