Constant light induces persistent Fos expression in rat intergeniculate leaflet.
Fos protein expression in retinorecipient suprachiasmatic nucleus (SCN) neurons is a marker of photic entrainment of circadian rhythms. Light-induced Fos in neurons of the intergeniculate leaflet (IGL) is not well-characterized. We compared Fos immunoreactivity (Fos-IR) in SCN and IGL neurons of rats housed under various lighting conditions and sacrificed at different phases of the circadian period. IGL neurons of rats that received 1 h-3 weeks of light exposure prior to sacrifice displayed Fos-IR, whereas the IGL of animals exposed only to darkness displayed little if any staining. In contrast with light-induced Fos in SCN neurons, Fos-IR was observed in the IGL regardless of circadian time. This work supports the idea that the IGL is involved in transmission of photic information to the SCN in rats.
Edelstein
K
K
Department of Psychology, Concordia University, Montreal, Canada.
Amir
S
S
D000818:Animals; D000918:Antibody Specificity; D002940:Circadian Rhythm / Q000502:physiology; D005829:Geniculate Bodies / Q000737:chemistry* / Q000502:physiology*; D007150:Immunohistochemistry; D008027:Light; D008297:Male; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis / Q000096:biosynthesis* / Q000276:immunology; D051381:Rats; D017208:Rats, Wistar; D012165:Retinal Ganglion Cells / Q000502:physiology; D013493:Suprachiasmatic Nucleus / Q000737:chemistry / Q000502:physiology
D016760:Proto-Oncogene Proteins c-fos