Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Daily profile of 5-HT release from the SCN region in hamsters maintained under constant dark (DD) for a minimum of 2 weeks. CT 12 represents the onset of subjective night as assessed by actograms. Each point represents the mean ± SEM for 6 animals. *p < 0.05 versus mean subjective day level.
