TRACING NEURONAL LINEAGES
A number of researches study how embryonic neurons find their positions by following the guides provided by radial glia and by settling where they find compatible membrane “stickiness” (Linda Faye Lehman & Giuseppe Perrella, How cortical interneurons find their address. BM&L-INTERNATIONAL, Views and News, 09/12, 2003), but the brain is an overwhelmingly complex organization. Is there any way of following the life lines of cells within this complexity? Can we track their wanderings from place of birth (proliferative zone) to their final position in the mature brain? On the face of it, with a jungle of 1011 cells, this seems a very tall order indeed. If we inject stem cells in the proliferative zones with a marker such as horseradish peroxidase subsequent cell divisions will so dilute the histochemical that it will soon be impossible to locate.
BM&L discussed two of the newer techniques: retrovirus tagging and enhancer trapping.