We cultured E13.5 whole DRG explants from wild-type and TauEWS-Pea3/+ Isl1Cre/+ embryos in the presence of NGF or NT-3 or in the absence of neurotrophins and analyzed neuronal survival and neurite outgrowth on matrigel substrate after 48 h in vitro. Without neurotrophic support, very few wild-type DRG neurons survived (Figure 4A). In contrast, culturing wild-type DRG with neurotrophic factors led to neuronal survival and neurite outgrowth. Addition of NGF, which supports survival of cutaneous afferents, resulted in straight and unbranched neurite outgrowth (Figure 4B), while cultures grown in the presence of NT-3, which supports survival of proprioceptive afferents, resulted in a highly branched neurite outgrowth pattern after 48 h in vitro (Figure 4C). Surprisingly, DRG neurons isolated from TauEWS-Pea3/+ Isl1Cre/+ embryos and cultured without neurotrophic support survived after 48 h in vitro and had established long and highly branched neurites (Figure 4D). Neither the pattern of neurite outgrowth nor neuronal survival changed significantly after application of either NGF or NT-3 (Figure 4E and 4F).