Figure 1.

Left panel is a confocal microscope image of a growth cone of a chick dorsal root ganglion neuron showing F-actin labeled with fluorescent phalloidin. Actin filaments fill the filopodia and small veil-like lamellipodia of the growth cone leading margin. The right panel is an electron micrograph of the branched network and bundles of actin filaments in the growth cone periphery in an area similar to that marked with an asterisk in the left panel. Right image is courtesy of Dr. Lorene Lanier, University of Minnesota.