To study cell fate in the cortex, one needs to be able identify a dividing cell early on, and then l

1
Class 17 ICQs
To study cell fate in the cortex, one needs to be
able identify a dividing cell early on, and then
later determine its identity (what it has
differentiated into).

• Tritiated thymidine is
• Incorporated into a dividing cell, and retained
  only in that cell
• Incorporated into a dividing cell this cell and
  its progeny will have the label

2
Neurons migrate to form cortical layers
superficial
deep

• What does this experiment tell you? (.5 pts)
• The superficial layers form first
• The deep layers form first
• The cells are committed to make a particular
  layer before they migrate
• The cells are not committed until after they
  migrate

3
Transplant precursor from E29 donor (early) to P1
host (late)
Cell transplanted after S phase
Cell transplanted in S phase

• What does this experiment tell you?
• The precursor cells are committed to their
  laminar fate
• The precursor cells are not always committed to
  their laminar fate

12.19
4
Is this plasticity maintained over time?
Transplant precursor from P1 donor to E29 host

• What does this allow you to conclude about
  cortical progenitor cells? (.5)
• There must be some intrinsic change in the
  precursor cells over time
• There could be a change in the precursors
  environment over time
• The fate of a precursor cell is restricted over
  time
• All of the above
• Ill accept all answers as correct

5
Class 18 ICQ (3 pts for participation)

• What does this experiment demonstrate (the frog
  eye rotation)?
• The neurons are committed to target a particular
  region of tectum
• The neurons are not committed to target a
  particular region of tectum
• The neurons can change where they target in
  response to their
• new location
• The neurons target the tectum randomly