585 research outputs found

    Afadin Signaling at the Spinal Neuroepithelium Regulates Central Canal Formation and Gait Selection

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    Skarlatou et al. report that afadin function in the developing spinal neuroepithelium controls organization of the midline. Afadin elimination from the motor neuron progenitor zone results in duplication of the central canal, aberrant wiring of dI4-5, V0, and V2a premotor neurons, and loss of left-right limb alternation.publishersversionpublishe

    Drosophila motor neuron boutons remodel through membrane blebbing coupled with muscle contraction

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    Funding Information: We would like to thank Telmo Pereira from the Microscopy Facility for technical support, the Fly Facility at Nova Medical Research; CONGENTO: consortium for genetically tractable organisms. We thank the Developmental Studies Hybridoma Bank, Bloomington Drosophila Stock Center and VDRC for antibodies and fly stocks. This work was supported by PTDC-01778/2022- NeuroDev3D to R.O.T. GEMiNI and PTDC/BIA-COM/0151/2020 to C.S.M and European Research Council H2020-GA 810207-ARPCOMPLEXITY to E.R.G. A.R.F. is supported with a PhD scholarship from Fundação para a Ciência e Tecnologia, Portugal, reference SFRH/BD/144488/2019, and J.P.M. with a reference SFRH/BD/130920/2017. This work also supported by iNOVA4Health (UIDB/04462/2020 and UIDP/04462/2020), and LS4FUTURE (LA/P/0087/2020). Funding Information: We would like to thank Telmo Pereira from the Microscopy Facility for technical support, the Fly Facility at Nova Medical Research; CONGENTO: consortium for genetically tractable organisms. We thank the Developmental Studies Hybridoma Bank, Bloomington Drosophila Stock Center and VDRC for antibodies and fly stocks. This work was supported by PTDC-01778/2022- NeuroDev3D to R.O.T. GEMiNI and PTDC/BIA-COM/0151/2020 to C.S.M and European Research Council H2020-GA 810207-ARPCOMPLEXITY to E.R.G.. A.R.F. is supported with a PhD scholarship from Fundação para a Ciência e Tecnologia, Portugal, reference SFRH/BD/144488/2019, and J.P.M. with a reference SFRH/BD/130920/2017. This work also supported by iNOVA4Health (UIDB/04462/2020 and UIDP/04462/2020), and LS4FUTURE (LA/P/0087/2020). Publisher Copyright: © 2023, The Author(s).Wired neurons form new presynaptic boutons in response to increased synaptic activity, however the mechanism(s) by which this occurs remains uncertain. Drosophila motor neurons (MNs) have clearly discernible boutons that display robust structural plasticity, being therefore an ideal system in which to study activity-dependent bouton genesis. Here, we show that in response to depolarization and in resting conditions, MNs form new boutons by membrane blebbing, a pressure-driven mechanism that occurs in 3-D cell migration, but to our knowledge not previously described to occur in neurons. Accordingly, F-actin is decreased in boutons during outgrowth, and non-muscle myosin-II is dynamically recruited to newly formed boutons. Furthermore, muscle contraction plays a mechanical role, which we hypothesize promotes bouton addition by increasing MN confinement. Overall, we identified a mechanism by which established circuits form new boutons allowing their structural expansion and plasticity, using trans-synaptic physical forces as the main driving force.publishersversionpublishe

    Comparison between two bone substitutes for alveolar ridge preservation after tooth extraction: Cone-beam computed tomography results of a non-inferiority randomized controlled trial

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    AIM To test the non-inferiority of demineralized bovine bone mineral (DBBM) compared to DBBM with 10% collagen (DBBM-C) for maintenance of bone volume after tooth extraction in the anterior maxilla. MATERIALS AND METHODS Sixty-six patients were randomly treated with DBBM or DBBM-C, both of which were covered with a collagen matrix for ridge preservation in the anterior maxilla. Cone-beam computed tomographic analysis was performed immediately and 4 months after treatment. The primary outcome, for which non-inferiority of DBBM was tested, was change in the horizontal ridge width 1 mm below the buccal alveolar crest (HW-1) 4 months after extraction. RESULTS Four months after extraction, HW-1 measured -1.60 mm ± 0.82 mm for DBBM-C, while the DBBM group showed a mean loss of -1.37 mm ± 0.84 mm (p = 0.28, 0.23 [95% CI: -0.19; 0.64]). The horizontal ridge width at 3 mm (HW-3) showed -0.98 mm (±0.67 mm) for DBBM-C and -0.84 mm (±0.62 mm) for DBBM (p = 0.40, 0.12 [95% CI: -0.19; 0.45]), and the horizontal ridge width at 5 mm (HW-5) showed -0.67 mm (±0.47 mm) for DBBM-C and -0.56 mm (±0.48 mm) for DBBM (p = 0.36, 0.11 [95% CI: -0.13; 0.34]). CONCLUSIONS The present clinical trial demonstrated non-inferiority of DBBM compared to DBBM-C for maintenance of alveolar bone volume 4 months after tooth extraction in the anterior maxilla

    Idades de deposição dos sedimentos da falésia de Itaguaré (Bertioga-SP) determinadas por luminescência opticamente estimulada

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    A região da foz do rio Itaguaré, localizada no Parque Estadual da Restinga de Bertioga-SP, apresenta uma miscelânea de processos sedimentares e formas de leito atuais gerados pela ação de marés, ondas e do próprio rio. Ocorrem também depósitos sedimentares quaternários expostos ao longo de falésia de dezenas de metros de extensão por até 4m de altura, formados por processos de ondas análogos aos observados na praia adjacente. Seus depósitos sedimentares são compostos por areias finas, moderadamente a bem selecionadas, com estratificação plano-paralela, tendo em sua porção inferior (~0,5m) icnofósseis de Ophiomorfa nodosa (galerias de Callichirus sp.). Esta sucessão sedimentar é indicativa de deposição sob o espraiamento de ondas, em condições regressivas, e com nível relativo do mar cerca de 1,4±1,0m acima do atual, estimado pela comparação da cota máxima de ocorrência do O. nodosa com o topo da biozona de Callichirus vivente. Duas amostras de sedimentos (Ber-01, basal, e Ber-02, topo) foram datadas por luminescência opticamente estimulada (LOE), com o uso do protocolo Single Aliquot Regeneration-dose (LOE-SAR). O método geocronológico por LOE-SAR indica, por premissa, a idade de última exposição à luz solar que, nesse caso, é a idade de deposição do sedimento. As medidas de dose equivalente ou paleodose obtidas em 18 (Ber-01) e 20 (Ber-02) alíquotas apresentaram baixos valores de dispersão (7,8% e 7,5%, respectivamente), calculados pelo parâmetro overdispersion de distribuição de dados. Esta baixa dispersão é o melhor indicador de que as amostras foram fotoesvaziadas previamente à deposição e soterradas com sinal LOE residual próximo de zero, e que, portanto, os processos de mistura pós-deposicionais são negligenciáveis para a interpretação dos resultados. As idades (Ber-01: 4,4±0,3 ka e Ber-02: 3,6±0,2 ka) são estratigraficamente coerentes e, além disso, compatíveis com as curvas do nível relativo do mar mais aceitas para a região, o que eleva a confiabilidade dos resultados

    Synthesis of beta-phenylchalcogeno-alpha, beta-unsaturated esters, ketones and nitriles using microwave and solvent-free conditions

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    A simple, clean and efficient solvent-free protocol was developed for hydrochalcogenation of alkynes containing a Michael acceptor (ester, ketone and nitrile) with phenylchalcogenolate anions generated in situ from the respective diphenyl dichalcogenide (Se, Te, S), using alumina supported sodium borohydride. This efficient and improved method is general and furnishes the respective (Z)-beta-phenylchalcogeno-<FONT FACE=Symbol>a,b</FONT>-unsaturated esters, ketones and nitriles, in good yield and higher selectivity, compared with those that use organic solvent and inert atmosphere. The use of microwave (MW) irradiation facilitates the procedure and accelerates the reaction

    The steroid-hormone ecdysone coordinates parallel pupariation neuromotor and morphogenetic subprograms via epidermis-to-neuron Dilp8-Lgr3 signal induction

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    Funding Information: We thank Drs. Carlos Ribeiro, Christen Mirth, Elio Sucena, Filip Port, Frank Schnorrer, Julien Colombani, Maria Dominguez, Maria Luisa Vasconcelos, Pierre Leopold, Simon Bullock, Rita Teodoro, Gerald Rubin, Melissa Harrison, Kate O’Connor-Giles, Jill Wildonger, Mariana Melani, Pablo Wappner, and Christian Wegener for fly stocks and reagents. We thank Ryohei Yagi and Konrad Basler for the LHV2 plasmid and Brain McCabe for the mhc-Gateway destination plasmid. We thank Carlos Ribeiro and Dennis Goldschmidt for help in designing and constructing one of the pupariation arenas and Mariana Melani, Pablo Wappner, Arash Bashirullah, and Filip Port for sharing resources and unpublished data. We thank Arash Bashirullah, Fillip Port, and Carlos Ribeiro for discussions and/or comments on the manuscript, and Jim Truman for discussions on Fraenkel’s pupariation factors. Stocks obtained from the Bloomington Drosophila Stock Center (NIH P40OD018537) were used in this study. Work in the Integrative Biomedicine Laboratory was supported by the European Commission FP7 (PCIG13-GA-2013-618847), by the FCT (IF/00022/2012; Congento LISBOA-01-0145-FEDER-022170, cofinanced by FCT/Lisboa2020; UID/Multi/04462/2019; PTDC/BEXBCM/1370/2014; PTDC/MED-NEU/30753/2017; PTDC/BIA-BID/31071/2017; FCT SFRH/BPD/94112/ 2013; SFRH/BD/94931/2013), the MIT Portugal Program (MIT-EXPL/BIO/0097/2017), and FAPESP (16/09659-3, 16/10342-4, and 17/17904-0). AG is a CONICET researcher, YV holds a CONICET postdoctoral fellowship and FPS and MJD hold a PhD fellowship from CONICET. Work in the Garelli lab was supported by ANPCyT (Agencia Nacional para la Promoción de la Ciencia y la Tecnología, PICT 2014-2900 and PICT 2017-0254) and CONICET (PIP11220150100182CO). Publisher Copyright: © 2021, The Author(s). Copyright: Copyright 2021 Elsevier B.V., All rights reserved.Innate behaviors consist of a succession of genetically-hardwired motor and physiological subprograms that can be coupled to drastic morphogenetic changes. How these integrative responses are orchestrated is not completely understood. Here, we provide insight into these mechanisms by studying pupariation, a multi-step innate behavior of Drosophila larvae that is critical for survival during metamorphosis. We find that the steroid-hormone ecdysone triggers parallel pupariation neuromotor and morphogenetic subprograms, which include the induction of the relaxin-peptide hormone, Dilp8, in the epidermis. Dilp8 acts on six Lgr3-positive thoracic interneurons to couple both subprograms in time and to instruct neuromotor subprogram switching during behavior. Our work reveals that interorgan feedback gates progression between subunits of an innate behavior and points to an ancestral neuromodulatory function of relaxin signaling.publishersversionpublishe
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