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31.
Kremer MC Christiansen F Leiss F Paehler M Knapek S Andlauer TF Förstner F Kloppenburg P Sigrist SJ Tavosanis G 《Current biology : CB》2010,20(21):1938-1944
How does the sensory environment shape circuit organization in higher brain centers? Here we have addressed the dependence on activity of a defined circuit within the mushroom body of adult Drosophila. This is a brain region receiving olfactory information and involved in long-term associative memory formation. The main mushroom body input region, named the calyx, undergoes volumetric changes correlated with alterations of experience. However, the underlying modifications at the cellular level remained unclear. Within the calyx, the clawed dendritic endings of mushroom body Kenyon cells form microglomeruli, distinct synaptic complexes with the presynaptic boutons of olfactory projection neurons. We developed tools for high-resolution imaging of pre- and postsynaptic compartments of defined calycal microglomeruli. Here we show that preventing firing of action potentials or synaptic transmission in a small, identified fraction of projection neurons causes alterations in the size, number, and active zone density of the microglomeruli formed by these neurons. These data provide clear evidence for activity-dependent organization of a circuit within the adult brain of the fly. 相似文献
32.
Alexander Ziegler Malte Ogurreck Thomas Steinke Felix Beckmann Steffen Prohaska Andreas Ziegler 《Biology direct》2010,5(1):45
Abstract
Advances in digital data acquisition, analysis, and storage have revolutionized the work in many biological disciplines such as genomics, molecular phylogenetics, and structural biology, but have not yet found satisfactory acceptance in morphology. Improvements in non-invasive imaging and three-dimensional visualization techniques, however, permit high-throughput analyses also of whole biological specimens, including museum material. These developments pave the way towards a digital era in morphology. Using sea urchins (Echinodermata: Echinoidea), we provide examples illustrating the power of these techniques. However, remote visualization, the creation of a specialized database, and the implementation of standardized, world-wide accepted data deposition practices prior to publication are essential to cope with the foreseeable exponential increase in digital morphological data. 相似文献33.
Cornelissen C Lüscher-Firzlaff J Baron JM Lüscher B 《European journal of cell biology》2012,91(6-7):552-566
Cytokines are key to control cellular communication. Interleukin-31 (IL-31) was recently discovered as a new member of the IL-6 family of cytokines. IL-31 signals through a heterodimeric receptor composed of OSMR and IL-31RA, a complex that stimulates the JAK-STAT, the RAS/ERK and the PI3K/AKT signal transduction pathways. The available data suggests that IL-31 is important for both innate and adaptive immunity in tissues that are in close contact with the environment, i.e. the skin, the airways and the lung, and the lining of the intestine. Enhanced expression of IL-31 is associated with a number of diseases, including pruritic diseases such as atopic dermatitis, but also in allergy and inflammatory bowel disease. In these tissues IL-31 coordinates the interaction of different immune cells, including T-cells, mast cells, and eosinophils, with epithelial cells. In this review we have summarized the available data on IL-31 and its receptor, their expression pattern and how they are regulated. We describe the current state of knowledge of the involvement of IL-31 in diseases, both in humans and in mouse models. From these studies it is becoming clear that IL-31 plays an important role in the proper functioning of the skin and of airway and intestinal epithelia. The findings available suggest that IL-31 might be an interesting target for directed drug therapy. 相似文献
34.
Hagen Preik-Steinhoff Malte Kelm 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1996,685(2):4563
All photometric or HPLC methods described to date have been unable to detect nitrite, a reliable marker of NO synthase activity, in human blood because of its rapid metabolism within the erythrocytes. We now elaborate on method to prevent nitrite degradation during sample preparation which in combination with high-performance anion-exchange chromatography and electrochemical detection allows a sensitive measurement of nitrite. A linear current response in the concentration range of 10–1000 nmol/l nitrite was observed yielding a correlation coefficient of 0.99. In addition, the combination of the electrochemical with a UV detector allowed us to simultaneously quantify nitrate one analytical run, which is the end product of NO/nitrite metabolism. Basal levels for nitrate and nitrite in human blood were determined with 25±4 μmol/l and 578±116 nmol/l (n=8), respectively and thus were in the same concentration range as expected from NO measurement in saline perfused isolated organs or cultured endothelial cells. Therefore, the presented method may be used to assess activity of endothelial constitutive NO synthase in humans under physiological and pathophysiological conditions. 相似文献
35.
Peter Waldeck Jeanette Iren Hagen Sveinn Are Hanssen Malte Andersson 《Journal of avian biology》2011,42(3):231-238
Conspecific brood parasitism (CBP) is an alternative reproductive tactic found in many animals with parental care. Parasitizing females lay eggs in the nests of other females (hosts) of the same species, which incubate and raise both their own and the foreign offspring. The causes and consequences of CBP are debated. Using albumen fingerprinting of eggs for accurately detecting parasitism, we here analyse its relation to female condition and clutch size in High Arctic common eiders Somateria mollissima borealis. Among 166 clutches in a Svalbard colony, 31 (19%) contained eggs from more than one female, and 40 of 670 eggs (6%) were parasitic. In 6 cases an active nest with egg(s) was taken over by another female. Many suitable nest sites were unoccupied, indicating that CBP and nest takeover are reproductive tactics, not only consequences of nest site shortage. Similarity in body mass between female categories suggests that condition does not determine whether a nesting female becomes parasitised. There was no evidence of low condition in parasites: egg size was similar in hosts and parasites, and parasitism was equally frequent early and late in the laying season. Meta‐analysis of this and 3 other eider studies shows that there is a cost of being parasitised in this precocial species: host females laid on average 7% fewer eggs than other females. 相似文献
36.
Marcelo R. de Carvalho Flávio A. Bockmann Dalton S. Amorim Carlos Roberto F. Brandão Mário de Vivo José L. de Figueiredo Heraldo A. Britski Mário C. C. de Pinna Naércio A. Menezes Fernando P. L. Marques Nelson Papavero Eliana M. Cancello Jorge V. Crisci John D. McEachran Robert C. Schelly John G. Lundberg Anthony C. Gill Ralf Britz Quentin D. Wheeler Melanie L. J. Stiassny Lynne R. Parenti Larry M. Page Ward C. Wheeler Julián Faivovich Richard P. Vari Lance Grande Chris J. Humphries Rob DeSalle Malte C. Ebach Gareth J. Nelson 《Evolutionary biology》2007,34(3-4):140-143
37.
Mona Hoppenrath Malte Elbrächter Hannelore Halliger Reinoud P. T. Koeman Alexander Krakhmalnyy Barbara Surek Katrin Erler Bernd Luckas 《Helgoland Marine Research》2007,61(3):157-165
Thecadinium yashimaense was recorded for the first time in France, Great Britain, The Netherlands, and Germany. The invasion and establishment of
the species in the German Bight was documented reliably and is presented here. The geographic expansion of the species from
the North Pacific to the North Atlantic Ocean is discussed. This bloom-forming, marine, sand-dwelling dinoflagellate was shown
to be non-toxic. Also Thecadinium kofoidii, the type species of the genus, was analyzed for potential toxin production and turned out to be non-toxic as well. 相似文献
38.
Silomon M Bauer I Bauer M Nolting J Paxian M Rensing H 《Cellular & molecular biology letters》2007,12(1):25-38
Stress response genes including heat shock proteins are induced under a variety of conditions to confer cellular protection.
This study investigated the role of calcium signaling in the induction of two stress response genes, heme oxygenase-1/hsp32
and hsp70, in isolated rat hepatocytes. Both genes were induced by cellular glutathione depletion. This induction could be
inhibited by BAPTA-AM. Culturing in a calcium-free medium prevented the induction of hsp70 gene expression after glutathione
depletion without affecting heme oxygenase-1 gene expression. Thapsigargin increased the gene expression of heme oxygenase-1
but not that of hsp70. Thapsigargin-induced heme oxygenase-1 induction was completely inhibited by BAPTA-AM. Incubation with
the Ca2+-ionophore A23187 augmented heme oxygenase-1 (two-fold) and hsp70 (5.2-fold) mRNA levels. Our data suggests a significant
role of Ca2+-dependent pathways in the induction of the two stress genes. An increase in the cytoplasmic Ca2+ activity seems to play a key role in the cascade of signaling leading to the induction of the two genes. However, the source
of Ca2+ that fluxes into the cytoplasm seems to be different. Our data provides evidence for a compartmentalization of calcium fluxes,
i.e. the Ca2+ flux from intracellular stores (e.g. the endoplasmic reticulum) plays a major role in the induction of heme oxygenase-1.
By contrast, Ca2+ flux from the extracellular medium seems to be a mechanism initiating the cellular signaling cascade leading to hsp70 gene
induction. 相似文献
39.
Klaschik Sven Lehmann Lutz E. Gebel Jürgen Book Malte Steinhagen Folkert W. Hoeft Andreas Stuber Frank 《World journal of microbiology & biotechnology》2011,27(9):2217-2222
Detection of bacterial DNA from laboratory-prepared specimens such as water, urine, and blood has the potential to improve
diagnostic tools in microbiology. A novel real-time PCR-based assay was developed and its performance and robustness were
evaluated for a panel of spiked suspensions of 15 clinically relevant bacteria. As low as ten colony forming units (CFU)/100 μl
were detectable. No cross-reactivity was observed, except for Staphylococcus aureus and Staphylococcus epidermidis. Nevertheless, S. aureus and S. epidermidis were reliably differentiated by melting curve analysis. The protocol was also validated with three groups containing a mixture
of five spiked bacteria each, with the result of reliable differentiation. This novel assay allows an exact identification
of 15 microbes relevant in intensive care medicine, including mixed infections, in a one run experiment in less than 4 h. 相似文献
40.
Malte C. Ebach Antonio G. Valdecasas Quentin D. Wheeler 《Cladistics : the international journal of the Willi Hennig Society》2011,27(5):550-557
There has been much discussion of the “taxonomic impediment”. This phrase confuses two kinds of impediment: an impediment to end users imposed by lack of reliable information; and impediments to taxonomy itself, which vary from insufficient funding to low citation rates of taxonomic monographs. In order to resolve both these types of impediment, taxonomy needs to be revitalized through funding and training taxonomists, as well as investing in taxonomic revisions and monographs rather than technological surrogates such as DNA barcoding.© The Willi Hennig Society 2011. 相似文献