191 research outputs found

    From Single Neurons to Behavior in the Jellyfish Aurelia aurita

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    Jellyfish nerve nets provide insight into the origins of nervous systems, as both their taxonomic position and their evolutionary age imply that jellyfish resemble some of the earliest neuron-bearing, actively-swimming animals. Here we develop the first neuronal network model for the nerve nets of jellyfish. Specifically, we focus on the moon jelly Aurelia aurita and the control of its energy-efficient swimming motion. The proposed single neuron model disentangles the contributions of different currents to a spike. The network model identifies factors ensuring non-pathological activity and suggests an optimization for the transmission of signals. After modeling the jellyfish's muscle system and its bell in a hydrodynamic environment, we explore the swimming elicited by neural activity. We find that different delays between nerve net activations lead to well-controlled, differently directed movements. Our model bridges the scales from single neurons to behavior, allowing for a comprehensive understanding of jellyfish neural control

    Gelingendes Leben - Krise als Chance für Person & Gesellschaft. Band II

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    • Peter Antes, Rel.wiss. • Petra Bahr, Theol. / Journ. • Matthias Beck Med./JS, AT • Gottfried Biewer, Bildungswiss., AT • Aladin El-Mafaalani, Pol.wiss.• Johannes Eurich, Diak.wiss. • Mario Feigel, Med. CH • Heike Gramkow, Manag.Dir. • Heinrich Greving, Heilpäd. • Udo Hahn, Theol.• Maria-C. Hallwachs, Stud., Beratg. schon betroffen • Walter Hirche, Min. a.D./Präs. Dt. UNESCO • Wolfgang Jantzen †, Soz. • Jochen-C. Kaiser, Hist. • Karl-J. Kemmelmeyer, Präs. Musikrat • Hermes Kick, Med.-Ethik • Waldemar Kippes Redemptorist JN • Ferdinand Klein, SoPäd., SK • Berthold Krüger, bpb • Christian Larsen, Arzt, CH • Ulrich Lilie Präs. Diak.W • Christian Lindmeier, SoPäd., DGfE • Ralf Meister, Bischof • Bertolt Meyer, Org.- u. Wirtschaftspsych, schon betroffen, CH • Peter Neher, Präs. Caritas • Ekkehard Nuissl, Dir. Dt. Inst. EB, DIE • Ulrich Pohl, Vorst. Bethel • Hartmann Römer, Physiker • David Roth, Lt. Hospiz • Hartmut Schlegel SoPäd. • Joachim Schoss, Unternehmer, schon betroffen, CH • Walter Surböck Med., AT• Karl-H. Steinmetz, Trad. Europ. Med., AT • Rudolf Tippelt, Bildg. Forschg. • Inge Wasserberg, Inklu.Beratg. • Walter Thirring †, Phys. CERN, C

    Lymphotoxin expression in human and murine renal allografts

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    The kidney is the most frequently transplanted solid organ. Recruitment of inflammatory cells, ranging from diffuse to nodular accumulations with defined microarchitecture, is a hallmark of acute and chronic renal allograft injury. Lymphotoxins (LTs) mediate the communication of lymphocytes and stromal cells and play a pivotal role in chronic inflammation and formation of lymphoid tissue. The aim of this study was to assess the expression of members of the LT system in acute rejection (AR) and chronic renal allograft injury such as transplant glomerulopathy (TG) and interstitial fibrosis/tubular atrophy (IFTA). We investigated differentially regulated components in transcriptomes of human renal allograft biopsies. By microarray analysis, we found the upregulation of LT beta, LIGHT, HVEM and TNF receptors 1 and 2 in AR and IFTA in human renal allograft biopsies. In addition, there was clear evidence for the activation of the NF kappa B pathway, most likely a consequence of LT beta receptor stimulation. In human renal allograft biopsies with transplant glomerulopathy (TG) two distinct transcriptional patterns of LT activation were revealed. By quantitative RT-PCR robust upregulation of LTa, LT beta and LIGHT was shown in biopsies with borderline lesions and AR. Immunohistochemistry revealed expression of LT beta in tubular epithelial cells and inflammatory infiltrates in transplant biopsies with AR and IFTA. Finally, activation of LT signaling was reproduced in a murine model of renal transplantation with AR. In summary, our results indicate a potential role of the LT system in acute renal allograft rejection and chronic transplant injury. Activation of the LT system in allograft rejection in rodents indicates a species independent mechanism. The functional role of the LT system in acute renal allograft rejection and chronic injury remains to be determined

    The V471A polymorphism in autophagy-related gene ATG7 modifies age at onset specifically in Italian Huntington disease patients

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    The cause of Huntington disease (HD) is a polyglutamine repeat expansion of more than 36 units in the huntingtin protein, which is inversely correlated with the age at onset of the disease. However, additional genetic factors are believed to modify the course and the age at onset of HD. Recently, we identified the V471A polymorphism in the autophagy-related gene ATG7, a key component of the autophagy pathway that plays an important role in HD pathogenesis, to be associated with the age at onset in a large group of European Huntington disease patients. To confirm this association in a second independent patient cohort, we analysed the ATG7 V471A polymorphism in additional 1,464 European HD patients of the “REGISTRY” cohort from the European Huntington Disease Network (EHDN). In the entire REGISTRY cohort we could not confirm a modifying effect of the ATG7 V471A polymorphism. However, analysing a modifying effect of ATG7 in these REGISTRY patients and in patients of our previous HD cohort according to their ethnic origin, we identified a significant effect of the ATG7 V471A polymorphism on the HD age at onset only in the Italian population (327 patients). In these Italian patients, the polymorphism is associated with a 6-years earlier disease onset and thus seems to have an aggravating effect. We could specify the role of ATG7 as a genetic modifier for HD particularly in the Italian population. This result affirms the modifying influence of the autophagic pathway on the course of HD, but also suggests population-specific modifying mechanisms in HD pathogenesis
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