The length of the longest thalamic axon was measured in whole-mount cocultures shown in Figure 5 between wild-type EGFP+ DTR or DTC explants and either wild-type (WT-VTel) or Netrin-1−/− (Netrin-1−/− VTel) telencephalon. This analysis reveals no significant differences (p > 0.05 according to nonparametric Mann-Whitney test) between the length of the longest DTR or DTC axon growing in wild-type or Netrin-1–deficient VTel, suggesting that Netrin-1 is not required in vivo for DTh axon extension. (2.89 MB TIF)