title: Cell-Autonomous Regulation of Dendritic Spine Density by PirB.
abstract: Synapse density on cortical pyramidal neurons is modulated by experience. This process is highest during developmental critical periods, when mechanisms of synaptic plasticity are fully engaged. In mouse visual cortex, the critical period for ocular dominance (OD) plasticity coincides with the developmental pruning of synapses. At this time, mice lacking paired Ig-like receptor B (PirB) have excess numbers of dendritic spines on L5 neurons; these spines persist and are thought to underlie the juvenile-like OD plasticity observed in adulthood. Here we examine whether PirB is required specifically in excitatory neurons to exert its effect on dendritic spine and synapse density during the critical period. In mice with a conditional allele of PirB (PirBfl/fl), PirB was deleted only from L2/3 cortical pyramidal neuronsin vivoby timedin uteroelectroporation of Cre recombinase. Sparse mosaic expression of Cre produced neurons lacking PirB in a sea of wild-type neurons and glia. These neurons had significantly elevated dendritic spine density, as well as increased frequency of miniature EPSCs, suggesting that they receive a greater number of synaptic inputs relative to Cre-neighbors. The effect of cell-specific PirB deletion on dendritic spine density was not accompanied by changes in dendritic branching complexity or axonal bouton density. Together, results imply a neuron-specific, cell-autonomous action of PirB on synaptic density in L2/3 pyramidal cells of visual cortex. Moreover, they are consistent with the idea that PirB functions normally to corepress spine density and synaptic plasticity, thereby maintaining headroom for cells to encode ongoing experience-dependent structural change throughout life.
authors.affiliation: Departments of Biology and Neurobiology, and Bio-X, James H. Clark Center, Stanford University , Stanford, California 94305.
authors.forename: George S
authors.identifier: 0000-0002-8623-7476
authors.initials: GS
authors.lastname: Vidal
authors.affiliation: Departments of Biology and Neurobiology, and Bio-X, James H. Clark Center, Stanford University , Stanford, California 94305.
authors.forename: Maja
authors.identifier: 0000-0002-2794-9406
authors.initials: M
authors.lastname: Djurisic
authors.affiliation: Departments of Biology and Neurobiology, and Bio-X, James H. Clark Center, Stanford University , Stanford, California 94305.
authors.forename: Kiana
authors.identifier: 0000-0002-7254-9428
authors.initials: K
authors.lastname: Brown
authors.affiliation: Departments of Biology and Neurobiology, and Bio-X, James H. Clark Center, Stanford University , Stanford, California 94305.
authors.forename: Richard W
authors.identifier: 0000-0002-2381-0300
authors.initials: RW
authors.lastname: Sapp
authors.affiliation: Departments of Biology and Neurobiology, and Bio-X, James H. Clark Center, Stanford University , Stanford, California 94305.
authors.forename: Carla J
authors.identifier: 0000-0001-5432-5917
authors.initials: CJ
authors.lastname: Shatz
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism; D002478:Cells, Cultured; D003423:Critical Period, Psychological; D049229:Dendritic Spines / Q000378:metabolism*; D023882:Dominance, Ocular; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D057507:Mice, 129 Strain; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D055369:Miniature Postsynaptic Potentials / Q000502:physiology; D009457:Neuroglia / Q000166:cytology / Q000378:metabolism; D009473:Neuronal Plasticity / Q000502:physiology; D017966:Pyramidal Cells / Q000166:cytology / Q000378:metabolism; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism*; D014793:Visual Cortex / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism*
chemical_list: C105949:Pirb protein, mouse; D011971:Receptors, Immunologic
keywords: PirB; cell-autonomous regulation; dendritic spine density; experience-dependent plasticity; structural plasticity; synapse pruning