Making Your Mind: Molecules, Motion, and Memory

Lecture 3 – Plan of Action: How the Spinal Cord Controls Movement

by Thomas M. Jessell, PhD

  1.  1.  Start of Lecture 3
  2.  2.  Welcome by HHMI President Dr. Thomas Cech
  3.  3.  Profile of Dr. Thomas Jessell
  4.  4.  Neural circuits: Controlling behavior, particularly movement
  5.  5.  Video: Computer analysis of human movement
  6.  6.  Damage to motor systems by disease and injury
  7.  7.  Motor neurons get input from multiple sources
  8.  8.  The proprioceptive sensory feedback system
  9.  9.  Demonstration: Testing a student's proprioceptive reflex
  10. 10.  Diagram showing the knee-jerk reflex circuit in action
  11. 11.  Proprioception is a subtle "sixth sense"
  12. 12.  Demonstration: Proprioception makes raising a mug easy
  13. 13.  Video: Without proprioception, standing or raising a mug is hard
  14. 14.  Genetically killing proprioceptive neurons in mice
  15. 15.  Video: Behavior of mice that lack proprioception
  16. 16.  Mice lacking proprioception have irregular muscle activity
  17. 17.  The role of interneurons in controlling motor patterns
  18. 18.  Video: Walking versus hopping
  19. 19.  Video: Dr. Jessell's muscle activity when he hops or walks
  20. 20.  The role of inhibition from the opposite side for walking
  21. 21.  Video: Mutant mice lacking crossed inhibition hop
  22. 22.  Reactivating damaged interneurons using sensory stimulation
  23. 23.  Q&A: Do organisms that change gait have multiple interneurons?
  24. 24.  Q&A: How do muscle spindles sense contraction?
  25. 25.  Q&A: How does polio cause paralysis?
  26. 26.  Q&A: Are proprioceptive signals also sent to the brain?
  27. 27.  Hearing and vision also control motor behavior
  28. 28.  Video: Ian Waterman—vision compensates for proprioceptive loss
  29. 29.  Demonstration: Touching thumb to fingers using proprioception
  30. 30.  Video: Waterman touching thumb/finger without visual feedback
  31. 31.  Functional MRI localizes brain activity during touching task
  32. 32.  Demonstration: Using spatial memory to clear an obstacle
  33. 33.  Analyzing a cat's ability to remember obstacle location
  34. 34.  Video: Cat remembers obstacle location for many minutes
  35. 35.  Animation: Neurons in parietal cortex are active during straddling
  36. 36.  Quantifying neuronal activity in Area 5 parietal cortex
  37. 37.  Inputs to motor neurons can compensate for one another
  38. 38.  Compensating for loss of motor neurons due to ALS
  39. 39.  Using stem cells to create new motor neurons in mice
  40. 40.  Using skin cells to make patient-specific stem cells
  41. 41.  Summary
  42. 42.  Q&A: Does proprioception compensate for vision in blind people?
  43. 43.  Q&A: Is all neuroscience research targeted to diseases?
  44. 44.  Q&A: Is ALS inherited?
  45. 45.  Q&A: What is the mechanism behind phantom limb pain?
  46. 46.  Q&A: Are motor neurons responsible for muscle atrophy in space?
  47. 47.  Closing remarks by HHMI President Dr. Thomas Cech


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