Fig. 1

Expression of neuronal markers between E8.5 and E10.5 in the developing mouse brain. All brains have been dissected and flatmounted in lateral view. a E9, Nhlh1 expression in the ventral midline corresponding to the nMLF. b E8.5, Tagln3 expression was ubiquitous through the ventral midline. c, d E8.5, Chga and Cntn2, no expression in the brain. e E8.5, Stmn2 expression in the rhombencephalon and rostral neural folds. At E9.5, expression of Nhlh1 (f), Tagln3 (g), Chga (h), Cntn2 (i) and Stmn2 (j) was present throughout the neuronal populations of the early axon scaffold tracts. At E10.5, expression of Nhlh1 (k), Tagln3 (l), Chga (m), Cntn2 (n) and Stmn2 (o) in neuronal populations of the established early axon scaffold (as delimited by dashed lined areas in k and l). There was also expression in the motor neurons, nIII and nIV. Arrowhead indicated expression of Nhlh1, Cntn2 and Stmn2 in the optic vesicle. In the rhombencephalon there was expression throughout the rhomomeres and locus coeruleus (LC). p E10.5, location of DMB (black longitudinal line) revealed by Pax6 in relation to Tagln3 expression. q E10.5, location of the nIII and nIV as well as the LC revealed by Phox2b compared with Nhlh1. r Schematic of early axon scaffold neuronal populations in the rostral brain. Each population has been colour coded. Grey longitudinal line represented the alar-basal boundary. Grey transversal line represented the DMB. For abbreviations see Table 1