Learning from Patients: The Science of Medicine

Lecture 3 – A Healthy Nervous System: A Delicate Balance

by Huda Zoghbi, MD
  1.  1.  Start of Lecture 3
  2.  2.  Introduction by HHMI President Dr. Thomas Cech
  3.  3.  Introductory interview with Dr. Huda Zoghbi
  4.  4.  The importance of balance and coordination in everyday life
  5.  5.  Cerebellum is important for coordination and balance
  6.  6.  Cell types found in cerebellum, particularly the Purkinje cell
  7.  7.  The story of an extended family with ataxia
  8.  8.  Video: A patient with spinocerebellar ataxia type 1 (SCA1)
  9.  9.  Cellular, clinical and genetic facts about SCA1
  10. 10.  Anticipation: Later generations have earlier onset of disease
  11. 11.  CAG trinucleotide repeat expansion causes SCA1
  12. 12.  Animation: Trinucleotide repeat expansion
  13. 13.  Number of CAG repeats influences the age of disease onset
  14. 14.  CAG repeat produces polyglutamine, causing many diseases
  15. 15.  Benefits of identifying disease-causing genes
  16. 16.  Q&A: How does the change in protein affect the cell?
  17. 17.  Q&A: Does the disease affect other involuntary functions?
  18. 18.  Q&A: What are the differences among the 22 types of SCAs?
  19. 19.  Q&A: How do the nerve cells express specific genes?
  20. 20.  Q&A: Are African-American families more vulnerable to SCA1?
  21. 21.  Is SCA1 caused by a loss-of-function mutation?
  22. 22.  Is SCA1 caused by a gain-of-function mutation?
  23. 23.  How do you tell that a mouse is ataxic?
  24. 24.  Video: Balance test for SCA1 mouse
  25. 25.  Purkinje cells degenerate in SCA1 mice
  26. 26.  Ataxin-1 accumulates in both SCA1 mice and patients
  27. 27.  Mutant ataxin-1 resists protein degradation and accumulates
  28. 28.  Ubiquitin acts as a marker for proteins targeted for degradation
  29. 29.  Animation: Ubiquitin and proteasome
  30. 30.  Protein accumulation occurs in many neurodegenerative diseases
  31. 31.  Using chaperones to counteract protein accumulation
  32. 32.  Using an SCA1 model in Drosophila to find disease modifiers
  33. 33.  Inhibiting protein kinase AKT can suppress the effects of SCA1
  34. 34.  Q&A: Are chaperones specific? Do they degrade other proteins?
  35. 35.  Q&A: Why do cells degrade proteins?
  36. 36.  Q&A: Does mutant ataxin interfere with proteasome function?
  37. 37.  Q&A: Does a mutation affect all cells?
  38. 38.  Closing remarks by HHMI President Dr. Thomas Cech


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