1,721,334 research outputs found
[Rezension zu:] Kirchhoff, Frank (2017): Von der Virgel zum Komma
No full textRezension zu Kirchhoff, Frank (2017): Von der Virgel zum Komma. Die Entwicklung der Interpunktion im Deutschen. Heidelberg: Universitätsverlag Winter (Germanistische Bibliothek 61), 253 S., ISBN 978-3-82536776-
Co-enrichment of Kir4.1 and AQP4 channels in spinal cord astrocytes suggests coupling of K+ flux and water transport: swelling experiments using transgenic mouse technology and time lapse 2-photon laser microscopy
No full textCo-enrichment of Kir4.1 and AQP4 channels in spinal cord astrocytes suggests coupling of K+ flux and water transport: swelling experiments using transgenic mouse technology and time lapse 2-photon laser microscopy
No full textTime-lapse 2-photon laser imaging to study microglia dynamics in the SOD1-mouse model of ALS
No full textTime-lapse 2-photon laser imaging to study microglia dynamics in the SOD1-mouse model of ALS
No full textAstroglial processes show spontaneous motility at active synaptic terminals in situ
No full textWithin the tripartite structure of vertebrate synapses, enwrapping astroglial processes regulate synaptic transmission by transmitter uptake and by direct transmitter release. We applied confocal and two-photon laser scanning microscopy to acutely isolated slices prepared from the brainstem of transgenic TgN(GFAP-EGFP) mice. In transversal sections fluorescently labelled astrocytes are evenly distributed throughout the tissue. Astroglial processes contacted neuronal somata and enwrapped active synaptic terminals as visualized using FM1-43 staining in situ. Here, at these synaptic regions astroglial process endings displayed a high degree of dynamic morphological changes. Two defined modes of spontaneous motility could be distinguished: (i) gliding of thin lamellipodia-like membrane protrusions along neuronal surfaces and (ii) transient extensions of filopodia-like processes into the neuronal environment. Our observations highlight the active role of astrocytes in direct modulation of synaptic transmission
Transgenic expression of fluorescent proteins in respiratory neurons
No full textWe screened transgenic mouse lines with Thy 1.2 promoter-induced expression of fluorescent proteins (FPs) for targeting of respiratory neuronal populations in the medulla oblongata. Respiratory neurons were found to be tagged by FPs within the ventral respiratory column (VRC), the pre-Botzinger complex (preBotC) and the rostral ventral respiratory group (rVRG) interneurons. A subset of neurons in the preBotC, labeled with the enhanced yellow fluorescent protein (EYFP), showed inspiratory activity during whole cell recordings from rhythmic slice preparations. Additionally, a subpopulation of EYFP-labeled preBotC neurons expressed both NK1 - and mu-opioid receptors. Furthermore, the spinal tri.-eminal nucleus, the lateral reticular nucleus (LRT) and the hypoglossal nucleus demonstrated intense EYFP expression whereas other regions of the medulla were devoid of neuronal EYFP labeling (e.g. the nucleus ambiguous). In conclusion, Thy 1.2-FP transgenic mice will facilitate the functional analysis of respiratory-related neurons in the medulla and improve the three dimensional analysis of cells contributing to this important neuronal circuit. (c) 2007 Elsevier B.V. All rights reserved
Kir4.1 channels regulate swelling of astroglial processes in experimental spinal cord edema
No full textIn glial cells, inwardly rectifying K+ channels (Kir) control extracellular [K+](o) homeostasis by uptake of K+ from the extracellular space and release of K+ into the microvasculature. Kir channels were also recently implicated in K+-associated water influx and cell swelling. We studied the time-dependent expression and functional implication of the glial Kir4.1 channel for astroglial swelling in a spinal cord edema model. In this CNS region, Kir4.1 is expressed on astrocytes from the second postnatal week on and co-localizes with aquaporin 4 (AQP4). Swelling of individual astrocytes in response to osmotic stress and to pharmacological Kir blockade were analyzed by time-lapse-two-photon laser-scanning microscopy in situ. Application of 30% hypotonic solution induced astroglial soma swelling whereas no swelling was observed on astroglial processes or endfeet. Co-application of hypotonic solution and Ba2+, a Kir channel blocker, induced prominent swelling of astroglial processes. In Kir4.1(-/-) mice, however, somatic as well as process swelling was observed upon application of 30% hypotonic solutions. No additional effect was provoked upon co-application with Ba2+. Our experiments show that Kir channels prevent glial process swelling under osmotic stress. The underlying Kir channel subunit that controls glial process swelling is Kir4.1, whereas changes of the glial soma are not substantially related to Kir4.1
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