Fig. 1

Central projection of PLL sensory neurons in an islet-GFP background, as seen (a) laterally and (b) dorsally. Rhombomere positions are based on the morphology of the various motor nuclei, particularly trigeminal in r2 and r3, facial in r6, and in r7 the small lateral line caudal efferent nucleus [33]. The exit of the facial nerve in r4, barely visible in (a), provides an additional landmark. DiI has been injected in the PLL nerve (PLLn). The cell bodies of the sensory neurons are gathered in the PLL ganglion (PLLg). Their axons enter the hindbrain posterior to the otic vesicle (ear) and bifurcate at the level of r6 (site of bifurcation marked by a thick arrow in both panels). They extend anteriorly to the level of r1 and posteriorly to the level of r7. The red and green images were taken at different focal planes. In this and in all following figures the dashed line indicates the sagittal plane and the scale bar is 20 microns.