title: LIS1-dependent retrograde translocation of excitatory synapses in developing interneuron dendrites.
abstract: Synaptic remodelling coordinated with dendritic growth is essential for proper development of neural connections. After establishment of synaptic contacts, synaptic junctions are thought to become stationary and provide fixed anchoring points for further dendritic growth. However, the possibility of active translocation of synapses along dendritic protrusions, to guide the proper arrangement of synaptic distribution, has not yet been fully investigated. Here we show that immature dendrites of γ-aminobutyric acid-positive interneurons form long protrusions and that these protrusions serve as conduits for retrograde translocation of synaptic contacts to the parental dendrites. This translocation process is dependent on microtubules and the activity of LIS1, an essential regulator of dynein-mediated motility. Suppression of this retrograde translocation results in disorganized synaptic patterns on interneuron dendrites. Taken together, these findings suggest the existence of an active microtubule-dependent mechanism for synaptic translocation that helps in the establishment of proper synaptic distribution on dendrites.
authors.affiliation: Department of Cellular Neurobiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Izumi
authors.initials: I
authors.lastname: Kawabata
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Kashiwagi
authors.forename: Kazuki
authors.initials: K
authors.lastname: Obashi
authors.forename: Masamichi
authors.initials: M
authors.lastname: Ohkura
authors.forename: Junichi
authors.initials: J
authors.lastname: Nakai
authors.forename: Anthony
authors.initials: A
authors.lastname: Wynshaw-Boris
authors.forename: Yuchio
authors.initials: Y
authors.lastname: Yanagawa
authors.forename: Shigeo
authors.initials: S
authors.lastname: Okabe
mesh_terms: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase / Q000235:genetics / Q000378:metabolism*; D000613:Aminobutyrates; D000818:Animals; D002478:Cells, Cultured; D003712:Dendrites / Q000502:physiology* / Q000648:ultrastructure; D004398:Dyneins / Q000378:metabolism; D007395:Interneurons / Q000502:physiology* / Q000648:ultrastructure; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000502:physiology; D009154:Mutation; D057907:Post-Synaptic Density / Q000502:physiology / Q000648:ultrastructure; D011554:Pseudopodia / Q000502:physiology / Q000648:ultrastructure; D034622:RNA Interference; D034741:RNA, Small Interfering; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission
chemical_list: D000613:Aminobutyrates; D008869:Microtubule-Associated Proteins; D034741:RNA, Small Interfering; C012223:alpha-aminobutyric acid; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase; C513190:Pafah1b1 protein, mouse; D004398:Dyneins