Fig. 3. Retrovirally transduced NLBs yield undifferentiated cells which proliferate and differentiate into neurons and glia. (A,F) 24 hours after infection, GFP-expressing cells were isolated by fluorescence activated cell sorting and replated. (B,G) Bright-field images of GFP+ cells 12 hours after plating from foetal and postnatal NLBs, respectively. (C,H) Fluorescent images of the same cells immunostained for TuJ1 and GFAP. Note that the only fluorescent signal detected is that of nuclear localised GFP. (D,I) Bright-field images of GFP+ cells isolated from foetal and postnatal NLBs and cultured for 10 days. (E,J) The corresponding fluorescent images after immunostaining for TuJ1 and GFAP. Note the presence of large numbers of neurons and glia at this stage.