title: The retinal projectome reveals brain-area-specific visual representations generated by ganglion cell diversity.
abstract: BACKGROUND
  Visual information is transmitted to the vertebrate brain exclusively via the axons of retinal ganglion cells (RGCs). The functional diversity of RGCs generates multiple representations of the visual environment that are transmitted to several brain areas. However, in no vertebrate species has a complete wiring diagram of RGC axonal projections been constructed. We employed sparse genetic labeling and in vivo imaging of the larval zebrafish to generate a cellular-resolution map of projections from the retina to the brain.
  
  
  RESULTS
  Our data define 20 stereotyped axonal projection patterns, the majority of which innervate multiple brain areas. Morphometric analysis of pre- and postsynaptic RGC structure revealed more than 50 structural RGC types with unique combinations of dendritic and axonal morphologies, exceeding current estimates of RGC diversity in vertebrates. These single-cell projection mapping data indicate that specific projection patterns are nonuniformly specified in the retina to generate retinotopically biased visual maps throughout the brain. The retinal projectome also successfully predicted a functional subdivision of the pretectum.
  
  
  CONCLUSIONS
  Our data indicate that RGC projection patterns are precisely coordinated to generate brain-area-specific visual representations originating from RGCs with distinct dendritic morphologies and topographic distributions.
authors.affiliation: Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany. Electronic address: erobles@neuro.mpg.de.
authors.forename: Estuardo
authors.initials: E
authors.lastname: Robles
authors.affiliation: Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany.
authors.forename: Eva
authors.initials: E
authors.lastname: Laurell
authors.affiliation: Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany.
authors.forename: Herwig
authors.initials: H
authors.lastname: Baier
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D021621:Imaging, Three-Dimensional; D007814:Larva / Q000502:physiology; D018613:Microscopy, Confocal; D012160:Retina / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000502:physiology*; D015027:Zebrafish / Q000254:growth & development / Q000502:physiology*