Clockwork Genes: Discoveries in Biological Time

Lecture 1 – Biology in Four Dimensions

by Joseph S. Takahashi, PhD

  1.  1.  Start of Lecture 1
  2.  2.  Introduction by HHMI President Dr. Thomas Cech
  3.  3.  Introductory interview with Dr. Joseph S. Takahashi
  4.  4.  What is circadian rhythm and what organisms have it?
  5.  5.  Video: Time-lapse video of reconstructing a dinosaur fossil
  6.  6.  Human-isolation experiment: Properties of circadian rhythm
  7.  7.  Activity-measurement experiment on a graduate student and Dr. Cech
  8.  8.  Video: Interview with Dr. Seymour Benzer
  9.  9.  Activity measurements from participating students
  10. 10.  Activity-measurement study reveals students' sleep patterns
  11. 11.  Self-assessment survey as a predictor of wake-up time on weekends
  12. 12.  Audience poll on preferred wake-up time
  13. 13.  Q&A: Can we compensate for lack of sleep?
  14. 14.  Q&A: How can you set your circadian clock?
  15. 15.  Q&A: How do people on a night shift deal with the schedule?
  16. 16.  Q&A: What would happen if you couldn't control your circadian clock?
  17. 17.  Q&A: Would irregular sleep patterns alter the circadian clock permanently?
  18. 18.  Q&A: Do all living things have a biological clock?
  19. 19.  Q&A: If your schedule is out of sync with your clock, would it affect you?
  20. 20.  Animation: Neuroanatomy of suprachiasmatic nucleus (SCN)
  21. 21.  Anatomy of SCN in rodents; cage for measuring mouse activity
  22. 22.  Video: Time-lapse video of mouse activity in the cage
  23. 23.  Mouse-activity chart for normal and SCN-lesioned mice
  24. 24.  SCN transplant experiment in SCN-lesioned hamsters
  25. 25.  Isolated SCN tissue oscillates with a circadian rhythm for more than 30 days
  26. 26.  Cells isolated from other parts of the body have circadian oscillations lasting several days
  27. 27.  Simulated jet lag: How fast do the body's clocks adjust?
  28. 28.  Summary of simulated jet-lag experiment
  29. 29.  Properties of individual neurons of SCN
  30. 30.  Higher level of organization of the clock in mammals
  31. 31.  Q&A: What effects would delayed shift of the body have?
  32. 32.  Q&A: How would human performance be affected if SCN were missing?
  33. 33.  Q&A: Do cancer cells exhibit circadian oscillations?
  34. 34.  Q&A: Do some animals have 12-hour tidal rhythms?
  35. 35.  Q&A: Where is the circadian clock located in other animals and plants?
  36. 36.  Q&A: Would circadian rhythms be different at high latitudes?
  37. 37.  Q&A: Can you really reset your clock by shining a light behind the knee?
  38. 38.  Q&A: If you travel often, could your body adjust faster?
  39. 39.  Q&A: Do isolated body clocks need the SCN for sync?
  40. 40.  Closing remarks by HHMI President Dr. Thomas Cech

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