title: Uncoupling dendrite growth and patterning: single-cell knockout analysis of NMDA receptor 2B.
abstract: N-methyl-D-aspartate receptors (NMDARs) play important functions in neural development. NR2B is the predominant NR2 subunit of NMDAR in the developing brain. Here we use mosaic analysis with double markers (MADM) to knock out NR2B in isolated single cells and analyze its cell-autonomous function in dendrite development. NR2B mutant dentate gyrus granule cells (dGCs) and barrel cortex layer 4 spiny stellate cells (bSCs) have similar dendritic growth rates, total length, and branch number as control cells. However, mutant dGCs maintain supernumerary primary dendrites resulting from a pruning defect. Furthermore, while control bSCs restrict dendritic growth to a single barrel, mutant bSCs maintain dendritic growth in multiple barrels. Thus, NR2B functions cell autonomously to regulate dendrite patterning to ensure that sensory information is properly represented in the cortex. Our study also indicates that molecular mechanisms that regulate activity-dependent dendrite patterning can be separated from those that control general dendrite growth and branching.
authors.affiliation: Department of Biology, Stanford University, Stanford, CA 94305, USA.
authors.forename: J Sebastian
authors.initials: JS
authors.lastname: Espinosa
authors.forename: Damian G
authors.initials: DG
authors.lastname: Wheeler
authors.forename: Richard W
authors.initials: RW
authors.lastname: Tsien
authors.forename: Liqun
authors.initials: L
authors.lastname: Luo
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D019521:Body Patterning / Q000235:genetics; D002118:Calcium / Q000378:metabolism; D002452:Cell Count; D002540:Cerebral Cortex / Q000166:cytology; D003712:Dendrites / Q000187:drug effects / Q000502:physiology*; D018891:Dentate Gyrus / Q000166:cytology; D003857:Deoxyuridine; D004622:Embryo, Mammalian; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout; D008954:Models, Biological; D009474:Neurons / Q000145:classification / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000172:deficiency / Q000235:genetics / Q000502:physiology*
chemical_list: C121001:NR2B NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate; D049452:Green Fluorescent Proteins; D010751:Phosphopyruvate Hydratase; D002118:Calcium; D003857:Deoxyuridine