1,720,970 research outputs found
Activity correlation imaging: visualizing function and structure of neuronal populations in the olfactory bulb
No full textFast simultaneous imaging of mitral cell populations reveals odor specificity of latency patterns
No full textSpatiotemporal resolution of Ca2+ signaling events by real time imaging of single B cells
No full textAbstractAntigen-induced B cell activation requires mobilization of the Ca2+ second messenger. This process is associated with the subcellular relocalization of signal effector proteins of the B cell antigen receptor such as the adaptor protein SLP65. Here we describe a broadly applicable live cell imaging method to simultaneously visualize intracellular Ca2+ flux profiles and the translocation of cytosolic signaling proteins to the plasma membrane in real time. Our approach delineated the kinetic hierarchy of Ca2+ signaling events in B cells and revealed a timely ordered contribution of various organelles to the overall Ca2+ signal. The developed experimental setup provides a useful tool to resolve the spatiotemporal signaling dynamics in various receptor signaling systems
Fast simultaneous imaging of mitral cell populations reveals odor specificity of latency patterns
No full textActivity correlation imaging: visualizing function and structure of neuronal populations in the olfactory bulb
No full textActivity Correlation Imaging: Visualizing Function and Structure of Neuronal Populations
No full textAbstractFor the analysis of neuronal networks it is an important yet unresolved task to relate the neurons' activities to their morphology. Here we introduce activity correlation imaging to simultaneously visualize the activity and morphology of populations of neurons. To this end we first stain the network's neurons using a membrane-permeable [Ca2+] indicator (e.g., Fluo-4/AM) and record their activities. We then exploit the recorded temporal activity patterns as a means of intrinsic contrast to visualize individual neurons' dendritic morphology. The result is a high-contrast, multicolor visualization of the neuronal network. Taking the Xenopus olfactory bulb as an example we show the activities of the mitral/tufted cells of the olfactory bulb as well as their projections into the olfactory glomeruli. This method, yielding both functional and structural information of neuronal populations, will open up unprecedented possibilities for the investigation of neuronal networks
Nucleotide-Induced Ca(2+) Signaling in Sustentacular Supporting Cells of the Olfactory Epithelium
No full textExtracellular purines and pyrimidines are important Signaling molecules acting via purinergic cell-surface receptors in neurons, glia, and glia-like cells such as sustentacular supporting cells (SCs) of the olfactory epithelium (OE). Here, we thoroughly characterize ATP-induced responses in SCs of the OE using functional Ca(2+) image The initial ATP-induced increase of the intracellular Ca(2+) concentration [Ca(2+)](i) always occurred in the apical part of SCs and subsequently propagated toward the basal lamina, indicating the occurrence of purinergic receptors I the apical part of SCs. The mean propagation velocity of the Ca(2+) signal within SCs was 17.10 +/- 1.02 mu m/s. ATP evoked increases in [Ca(2+)](i) in both the presence and absence of extracellular Ca(2+). Depletion of the intracellular Ca(2+) stores abolished the responses. This shows that the ATP-induced [Ca(2+)](i) increases were in large part, if not entirely, due to the activation of G protein-coupled receptors followed by Ca(2+) mobilization from intracellular stores, suggesting an involvement of P2Y receptors. The order of potency of the applied purinergic agonists was UTP > ATP > ATP-gamma S (with all others being only weakly active or inactive). The ATP-induced [Ca(2+)](i) increases could be reduced by the purinergic antagonists PPADS and RB2, but not by suramin. Our findings suggest that extracellular nucleotides in the OE activate SCs via P2Y(2)/P2Y(4)-like receptors and initiate a characteristic intraepithelial Ca(2+) wave. (C) 2008 Wiley-Liss, Inc.DFG Research Cente
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