In mammals, the controlling clock component that generates a 24-hour rhythm is the suprachiasmatic nucleus (SCN), located in a part of the brain called the hypothalamus. The SCN produces a signal that can keep the rest of the body on an approximately 24-hour schedule. This animation illustrates...
This animation shows the molecular interactions involved in the negative feedback loop responsible for circadian rhythms in mammals.
This animation series shows four experiments that compare the activity patterns of a wild-type fly keeping a normal schedule with those of a mutant fly apparently following a 19-hour internal clock.
Watch these animations display the dynamic orchestration of the molecular events of the Drosophila biological clock.
Are you a night owl or a morning lark? Noted researcher Dr. Seymour Benzer discusses how the difference between he and his wife sparked his interest in the topic of biological clocks.
The bobtail squid swims during the night to hunt. During the day, it burrows to hide from predators.
Dr. Benzer is joined by Dr. Ron Konopka for a brief discussion of how the per gene is involved in mammalian clocks.
A brief interview with Dr. Takahashi.
This time-lapse videoclip shows human circadian activity while assembling a T. rex skeleton.
This time-lapse videoclip illustrates a mouse's nocturnal behavior.
Four lectures highlight the research of two scientists who have made groundbreaking discoveries elucidating the molecular basis of circadian clocks—the internal timekeepers that govern fluctuations in behavior and physiology on a 24-hour cycle.
Dr. Joseph Takahashi takes us on an exciting journey into a very special region of the brain—the biological clock that governs our physiology and certain behaviors.
Although tiny in size, the fruit fly has had a major impact on our understanding of circadian rhythms.
Dr. Rosbash discloses how scientists have persuaded Mother Nature to reveal the inner workings of the fruit fly's biological clock.
Dr. Takahashi describes the powerful strategies that he and others have harnessed for understanding biological clocks in mammals.
This survey, developed by Horne and Ostberg, will let you determine if you are a morning or an evening person.
A text transcript of the 2000 Holiday Lectures on Science, Clockwork Genes: Discoveries in Biological Time.
A chapter list to accompany the DVD.
A guide written for teachers to accompany the 2000 Holiday Lectures on Science.