Neuronal expression for non-transcription factor candidate target genes. (A-C) pcdh8 is expressed in medial and intermediate stripes (arrowheads) of primary neurons, in one posterior stripe between the two stripes of primary neurons, and in the anterior domain of the neural plate at stage 15, and in the spinal cord (white arrows) and some domains in the brain at stages 23 and 28. (D-F) peripherin is expressed in the trigeminal placodes (yellow arrows) and three stripes of primary neurons (arrowheads) at stage 15, and in the trigeminal placodes, olfactory placodes (black arrow), spinal cord, retina and many domains in the brain at stages 23 and 28. (G-I) greb1 is expressed as a band in the prospective midbrain/hindbrain region at stage 15, and in the midbrain/hindbrain region and spinal cord at stage 23, and in the olfactory placodes, spinal cord, and many domains in the brain at stage 28. (J,K) nf-m is not expressed at stage 15, but at stages 23 and 28 it is expressed in the trigeminal placodes and spinal cord. (L-N) kcnk5 is weakly expressed from anterior to posterior along the dorsal midline, with stronger expression in the anterior end of the neural fold at stage 15. It is expressed in retina, otic placode, and several domains in the brain at stages 23 and 28, and in spinal cord at stage 28. (O-Q) activin beta b is expressed in two bands in the prospective midbrain/hindbrain region and diffusely throughout the anterior neural plate at stage 15, and it is expressed in the retina and some brain domains at stages 23 and 28. Stage 15 embryos show dorsal views, and stages 23 and 28 embryos show lateral views.