Making Your Mind: Molecules, Motion, and Memory

Lecture 2 – Building Brains: The Molecular Logic of Neural Circuits

by Thomas M. Jessell, PhD

  1.  1.  Start of Lecture 2
  2.  2.  Welcome by HHMI Vice President Dr. Peter Bruns
  3.  3.  Profile of Dr. Thomas Jessell
  4.  4.  Assembly of neural circuits and behavior
  5.  5.  Human development from egg to adult
  6.  6.  Comparing the brain to a cell phone
  7.  7.  Zooming in on circuits and single neurons
  8.  8.  Synapses are the points of communication between neurons
  9.  9.  Animation: Molecular mechanism of synaptic function
  10. 10.  How do neurons differentiate during development?
  11. 11.  Animation: Development of the human embryonic brain
  12. 12.  Specific genes control early patterns of brain development
  13. 13.  A young neuron's location determines its ultimate identity
  14. 14.  Animation: Signal molecules trigger transcription factors
  15. 15.  Studying simple motor circuits in the spinal cord
  16. 16.  Motor neuron type derives from position in the neural tube
  17. 17.  Sonic hedgehog (SHH): An important signaling molecule
  18. 18.  Eye position depends on SHH signaling
  19. 19.  Demonstration: SHH concentration and eye position
  20. 20.  Blocking SHH signaling can create a cyclops
  21. 21.  Q&A: Do signal molecules have to be present throughout cell life?
  22. 22.  Q&A: Can cell type be changed after initial signaling?
  23. 23.  Q&A: How do cells secrete the correct amount of signal?
  24. 24.  Demonstration: The electrical activity of Dr. Jessell's arm
  25. 25.  Neurons use growth cones to find partner cells
  26. 26.  Video: Growth cones in action
  27. 27.  Neuronal pathways are like a subway system
  28. 28.  Video: Long-distance neuronal path-finding
  29. 29.  Neuronal path-finding by attraction and repulsion
  30. 30.  Video: Contact repulsion of a growth cone
  31. 31.  Repellant cues and motor neuron path-finding
  32. 32.  Animation: Repellant ephrin signals guide limb innervation
  33. 33.  Finding the right partner in a very crowded brain
  34. 34.  Binary choices produce specific neuronal connections
  35. 35.  Gene knock-outs reveal importance of repulsive signals
  36. 36.  Some synapses are stabilized and others eliminated
  37. 37.  Synaptic stabilization proteins implicated in autism
  38. 38.  Summary
  39. 39.  Q&A: What causes synaptic elimination?
  40. 40.  Q&A: Connection between synapse activity and intelligence?
  41. 41.  Q&A: When does most axon formation occur in development?
  42. 42.  Closing remarks by HHMI Vice President Dr. Peter Bruns


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