Work in the Helmbacher laboratory was supported by funds from the CNRS (ATIP grant), FRM (Fondation pour la Recherche M icale, Equipe FRM 2007), AFM (Association Fran ise contre les Myopathies), FdF (Fondation de France), ARC (Association pour la Recherche contre le Cancer) and ANR (Agence Nationale de la Recherche, ANR Neuro 2007). The contributions of the Region Provence Alpes C es d'Azur and Aix-Marseille Universit?for the IBDM animal facility, and of the France-BioImaging/PICsL infrastructure (ANR-10-INSB-04-01) for the imaging facility are also acknowledged.References 1.11.20. J Neurosci 2011, 31:11144?1158. EMBO J 2004, 23:3803?814. Work in the Maina lab by FM was supported by FRM, AFM, FdF, ARC, Fondation Bettencourt-Schueller and INCa (Institut National du Cancer).14.21. 2.8..Lamballe F, Genestine M, Caruso N, Arce V, Richelme S, Helmbacher F, Maina F: Pool-specific regulation of motor neuron survival by neurotrophic support. Mol Cell 2001, 7:1293?306. 3.23.Polleux F, Ince-Dunn G, Ghosh A: Transcriptional regulation of vertebrate axon guidance and PTC-209 manufacturer synapse formation. Medina DL, Sciarretta C, Calella AM, Von Bohlen Und Halbach O, Unsicker K, Minichiello L: TrkB regulates neocortex formation through the Shc/PLCmediated control of neuronal migration.12.13. Kanning KC, Kaplan A, Henderson CE: Motor neuron diversity in development and disease. Polleux 10ul Pipette tips F, Ince-Dunn G, Ghosh A: Transcriptional regulation of vertebrate axon guidance and synapse formation.19. Shneider NA, Brown MN, Smith CA, Pickel J, Alvarez FJ: Gamma motor neurons express distinct genetic markers at birth and require muscle spindle-derived GDNF for postnatal survival.15. Curr Top Dev Biol 2009, 87:119?48. Genes Dev 2002, 16:633?45. Neural Dev 2009, 4:42.9. Postigo A, Calella AM, Fritzsch B, Knipper M, Katz D, Eilers A, Schimmang T, Lewin GR, Klein R, Minichiello L: Distinct requirements for TrkB and TrkC signaling in target innervation by sensory neurons.22.17. Received: 1 July 2014 Accepted: 4 July4. Dasen JS: Transcriptional networks in the early development of sensory-motor circuits. 7.18. Nat Rev Neurosci 2007, 8:331?40.5. Science 1997, 278:2075?080.10. Encinas M, Tansey MG, Tsui-Pierchala BA, Comella JX, Milbrandt J, Johnson EM Jr: c-Src is required for glial cell line-derived neurotrophic factor (GDNF) family ligand-mediated neuronal survival via a phosphatidylinositol-3 kinase (PI-3 K)-dependent pathway. J Neurosci 2001, 21:1464?472. Pawson T, Scott JD: Signaling through scaffold, anchoring, and adaptor proteins.16.6. FH wrote the manuscript with proofreading by FM. Final approval was given by all authors. Annu Rev Neurosci 2010, 33:409?40.