The regenerative ability of planarians is truly remarkable - they can regenerate their entire body from a tiny tissue fragment. Of particular interest is how the brain regenerates. On p. 1679, Agata and colleagues now show that the planarian clathrin heavy chain(DjCHC) gene, which functions in endocytosis, is required for neurite extension and maintenance during regeneration but not for neuronal differentiation. They used a novel in vitro cell culture system in which primary cultures of planarian neurons from regenerated heads were sorted(according to neuronal marker expression) by fluorescence-activated cell sorting (FACS), following the RNAi knockdown of genes that are expressed in the regenerating CNS. This in vitro assay revealed that neurite extension but not neuronal differentiation depends on DjCHC. In uncut planarians,the patterning and differentiation of neural cells is normal despite the RNAi knockdown of DjCHC; however, neurites subsequently regress and neural cells die, resulting in an atrophied CNS. This surprising link between endocytosis and CNS regeneration will be of interest to both neurobiologists and investigators of regeneration.