title: K+channel reorganization and homeostatic plasticity during postembryonic development: biophysical and genetic analyses in acutely dissociated Drosophila central neurons.
abstract: Intrinsic electric activities of neurons play important roles in establishing and refining neural circuits during development. However, how the underlying ionic currents undergo postembryonic reorganizations remains largely unknown. Using acutely dissociated neurons from larval, pupal, and adult Drosophila brains, we show drastic re-assemblies and compensatory regulations of voltage-gated (IKv) and Ca2+-activated (IK(Ca)) K+currents during postembryonic development. Larval and adult neurons displayed prominent fast-inactivating IKv, mediated by the Shaker (Sh) channel to a large extent, while in the same neurons IK(Ca)was far smaller in amplitude. In contrast, pupal neurons were characterized by large sustained IKvand prominent IK(Ca), encoded predominantly by the slowpoke (slo) gene. Surprisingly, deletion of Sh in the ShMnull mutant removed inactivating, transient IKvfrom large portions of neurons at all stages. Interestingly, elimination of Sh currents was accompanied by upregulation of non-Sh transient IKv. In comparison, the slo1mutation abolished the vast majority of IK(Ca), particularly at the pupal stage. Strikingly, the deficiency of IK(Ca)in slo pupae was compensated by the transient component of IKvmediated by Sh channels. Thus, IK(Ca)appears to play critical roles in pupal development and its absence induces functional compensations from a specific transient IKvcurrent. While mutants lacking either Sh or slo currents survived normally, Sh;;slo double mutants deficient in both failed to survive through pupal metamorphosis. Together, our data highlight significant reorganizations and homeostatic compensations of K+currents during postembryonic development and uncover previously unrecognized roles for Sh and slo in this plastic process.
authors.affiliation: a Department of Neurobiology and Biophysics , School of Life Sciences, University of Science and Technology of China , Hefei , China.|b Institute of Neuroscience and Key Laboratory of Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai , China.|c New England Primate Research Center, Harvard Medical School , Southborough , MA , USA.
authors.forename: Taixiang
authors.initials: T
authors.lastname: Saur
authors.affiliation: d Department of Biology , University of Iowa , Iowa City , IA , USA.
authors.forename: I-Feng
authors.initials: IF
authors.lastname: Peng
authors.affiliation: a Department of Neurobiology and Biophysics , School of Life Sciences, University of Science and Technology of China , Hefei , China.|b Institute of Neuroscience and Key Laboratory of Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai , China.
authors.forename: Peng
authors.initials: P
authors.lastname: Jiang
authors.affiliation: a Department of Neurobiology and Biophysics , School of Life Sciences, University of Science and Technology of China , Hefei , China.|b Institute of Neuroscience and Key Laboratory of Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai , China.
authors.forename: Neng
authors.initials: N
authors.lastname: Gong
authors.affiliation: c New England Primate Research Center, Harvard Medical School , Southborough , MA , USA.
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Yao
authors.affiliation: a Department of Neurobiology and Biophysics , School of Life Sciences, University of Science and Technology of China , Hefei , China.|b Institute of Neuroscience and Key Laboratory of Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai , China.
authors.forename: Tian-Le
authors.initials: TL
authors.lastname: Xu
authors.affiliation: a Department of Neurobiology and Biophysics , School of Life Sciences, University of Science and Technology of China , Hefei , China.|b Institute of Neuroscience and Key Laboratory of Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai , China.|d Department of Biology , University of Iowa , Iowa City , IA , USA.
authors.forename: Chun-Fang
authors.initials: CF
authors.lastname: Wu
mesh_terms: D000818:Animals; D004330:Drosophila / Q000502:physiology*; D006706:Homeostasis / Q000502:physiology; D055495:Neurogenesis / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D015221:Potassium Channels / Q000378:metabolism*
chemical_list: D015221:Potassium Channels
keywords: Ca2+-activated K+ current; Sh channels; Whole-cell current; adult; larva; pupa; slo channels; voltage-gated K+ current