Spontaneous circadian and light-induced expression of junB mRNA in the hamster suprachiasmatic nucleus.
We examined both spontaneous and light-evoked expression of junB mRNA in the hamster suprachiasmatic nucleus (SCN), an endogenous circadian pacemaker. junB was expressed in the SCN in response to a light pulse during the subjective night and early subjective day as well as spontaneously during the transition from subjective night to subjective day. Light-evoked expression was strongest in the ventral SCN, while spontaneous expression was stronger in the dorsal SCN. Spontaneous expression began around subjective dawn and persisted for at least 4 h into the subjective day. The expression of junB mRNA may play a role in both phase-shifting responses to light and in spontaneous oscillation of the SCN pacemaker.
Department of Psychology, Dalhousie University, Halifax, Nova Scotia, Canada. rusak@ac.dal.ca
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Guido
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Rusak
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Robertson
D000704:Analysis of Variance; D000818:Animals; D001483:Base Sequence; D002940:Circadian Rhythm; D006224:Cricetinae; D003624:Darkness; D016758:Genes, jun; D007700:Kinetics; D008027:Light; D008297:Male; D008647:Mesocricetus; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D009928:Organ Specificity; D016755:Proto-Oncogene Proteins c-jun / Q000096:biosynthesis*; D012333:RNA, Messenger; D013493:Suprachiasmatic Nucleus / Q000502:physiology* / Q000528:radiation effects; D014158:Transcription, Genetic
D015345:Oligonucleotide Probes; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger