title: Lamination Speeds the Functional Development of Visual Circuits.
abstract: A common feature of the brain is the arrangement of synapses in layers. To examine the significance of this organizational feature, we studied the functional development of direction-selective (DS) circuits in the tectum of astray mutant zebrafish in which lamination of retinal ganglion cell (RGC) axons is lost. We show that although never laminar, the tuning of DS-RGC axons targeting the mutant tectum is normal. Analysis of mutant tectal neurons at late developmental stages reveals that directional tuning is indistinguishable from wild-type larvae. Furthermore, we show that structural plasticity of tectal dendrites and RGC axons compensates for the loss of lamination, establishing connectivity between DS-RGCs and their normal tectal targets. However, tectal direction selectivity is severely perturbed at earlier developmental stages. Thus, the formation of synaptic laminae is ultimately dispensable for the correct wiring of direction-selective tectal circuits, but it is crucial for the rapid assembly of these networks.
authors.affiliation: MRC Centre for Developmental Neurobiology, King's College London, Guy's Hospital Campus, London, SE1 1UL, UK. Electronic address: nikolas.nikolaou@kcl.ac.uk.
authors.forename: Nikolas
authors.initials: N
authors.lastname: Nikolaou
authors.affiliation: MRC Centre for Developmental Neurobiology, King's College London, Guy's Hospital Campus, London, SE1 1UL, UK. Electronic address: martin.meyer@kcl.ac.uk.
authors.forename: Martin P
authors.initials: MP
authors.lastname: Meyer
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D018274:Electroporation; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology*; D007814:Larva; D009154:Mutation / Q000235:genetics; D009415:Nerve Net / Q000502:physiology*; D009949:Orientation / Q000502:physiology*; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism; D012160:Retina / Q000166:cytology* / Q000254:growth & development; D012165:Retinal Ganglion Cells / Q000378:metabolism; D013477:Superior Colliculi / Q000166:cytology* / Q000254:growth & development; D014795:Visual Pathways / Q000502:physiology*; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism; D000097905:Roundabout Proteins
chemical_list: D011971:Receptors, Immunologic; D029961:Zebrafish Proteins; C498889:robo2 protein, zebrafish; D000097905:Roundabout Proteins