PDGF-AA Soaked Bead Implantation Affected the NCC Migration. Fluorescent imaging of the cells expressing EGFP, which shows the migration pattern of NCCs in an E9.5 P0-Cre/CAG-CAT-EGFP embryo after the implantation of a control bead (A) or of a PDGF-AA soaked bead (B) in the cranial region. Each figure is an individual frame from a time-lapse movie. The time interval between frames is indicated between the figures. Three differently colored curved arrows (red, yellow, and blue) represent examples of tracing for three distinct migrating NCCs. White circles with dotted lines indicate the position of the implanted bead (n = 5 in each bead implantation).