Abstract
In mammals, the suprachiasmatic nucleus (SCN) of the hypothalamus appears to act as a circadian clock. The SCN vasoactive intestinal polypeptide-like immunoreactive neurons, which may act to mediate photic information in the SCN, receive input from neurons immunoreactive for somatostatin (SST). Therefore we investigated the role of SST as a transmitter for entrainment by analyzing the phase-resetting effect of SST on the circadian rhythm of SCN firing activity. Perfusion of SST increased 2-deoxyglucose uptake at circadian time (CT) 18, but not at CT6. A 1-h or 15-min treatment with SST produced phase delays when it was administered at CT13-14 and phase advances at CT22-23. Thus SST-induced phase changes are similar to those for light pulses to animals under constant darkness. The present findings suggest that SST is a transmitter for mediating information of entrainment to circadian clocks within the SCN.
Original language | English |
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Pages (from-to) | R1199-R1204 |
Journal | American Journal of Physiology - Regulatory Integrative and Comparative Physiology |
Volume | 265 |
Issue number | 5 34-5 |
DOIs | |
Publication status | Published - 1993 |
Externally published | Yes |
Keywords
- brain slice
- metabolic rhythm
- peptide
- phase-response curve
ASJC Scopus subject areas
- Physiology
- Physiology (medical)