Introduction to Circadian Biology

By Isara Laothamatas

Three Criteria of Circadian Rhythm

• Rhythm has an endogenous free-running period of approximately ~24h

• Rhythms are entrainable by external cues

• Rhythms exhibit temperature compensation

PLoS One. 2008;3(12):e3884. doi: 10.1371/journal.pone.0003884. Epub 2008 Dec 8

Phase Response Curve

http://www.docudharma.com/diary/15742/the-idea-of-order-in-the-celestial-clockwork

SCN Transplantation Experiment

2118 Sollars et al. J Neurosci. 1995 Mar;15(3 Pt 2):2109-22.

Discovery of Clock gene

Takahashi, et al. (1994)

Discovery of Clock gene

Takahashi, et al. (1994)

Discovery of Clock gene

Takahashi, et al. (1994)

Transcriptional Feedback Loop Regulation

UT Southwestern Medical Center

UT Southwestern Medical Center

• Six Nobel laureates since 1985

• 23 members of the National Academy of Sciences

• 19 members of the National Academy of Medicine

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• 11 Howard Hughes Medical Institute investigators