ICQs17,18.ppt

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 Class 17 ICQs Neurons migrate to form cortical layers: 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 superficial deep Transplant precursor from E29 donor (early) to P1 host (late): 12.19 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 Transplant precursor from P1 donor to E29 host Is this plasticity maintained over time? Transplants go to 2/3 1 2/3 4 5 6 Host cells migrate to 5/6 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 precursor’s environment over time The fate of a precursor cell is restricted over time All of the above I’ll accept all answers as correct 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