Abstract
Mammalian circadian rhythmicity is endogenously generated by a pacemaker in the suprachiasmatic nuclei and precisely entrained to the 24-hr day/night cycle by periodic environmental light cues. We show that light alters the immunoreactive levels of a transcriptional regulatory protein, Fos, in the suprachiasmatic nuclei of albino rats. Photic regulation of Fos immunoreactivity does not occur in other retino-recipient brain areas except for the intergeniculate leaflet, which appears to be involved in mediating some of the complex effects of light on expressed circadian rhythms. Our results point to a promising new functional marker for the cellular effects of light and suggest that the expression of Fos or a related nuclear protein may be part of the mechanism for photic entrainment of the circadian clock to environmental light/dark cycles. (.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 5959-5962 |
| Number of pages | 4 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 87 |
| Issue number | 15 |
| State | Published - 1990 |
| Externally published | Yes |
Keywords
- Circadian rhythm
- Hypothalamus
- Transcription factor
ASJC Scopus subject areas
- Genetics
- General