Large dense-core vesicles (LDCVs) were labelled in cultured bovine adrenal chromaffin cells expressing fluorescent chimaeric 'cargo' proteins that were targeted to these secretory vesicles. When the cells were stimulated with nicotine 48 h after transduction, the fractional loss of fluorescent LDCVs was much greater than the fractional catecholamine secretion, implying selective release of newly assembled vesicles. This was confirmed using a fluorescent 'timer' construct that changes its fluorescence emission from green to red over several hours, and by measurement of the location and mobility of LDCVs in live cells by confocal fluorescence microscopy. Newly assembled (green) LDCVs were located mostly in peripheral regions of the cells, were virtually immobile and could be released by nicotine, but not by Ba2+; in contrast, older (red) LDCVs were centrally located and relatively mobile, and their exocytotic release was triggered by Ba2+, but not by nicotine. We describe the image restoration procedure that is necessary in order to analyse the behaviour of LDCVs labelled with this construct.
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http://dx.doi.org/10.1042/bst0310851 | DOI Listing |
Biophys J
January 2025
National Institute of Neurological Disorders and Stroke, Bethesda, Maryland. Electronic address:
Dense-core vesicles (DCVs) are found in various types of cells, such as neurons, pancreatic β- cells, and chromaffin cells. These vesicles release transmitters, peptides, and hormones to regulate diverse functions, such as the stress response, immune response, behavior, and blood glucose levels. In traditional electron microscopy after chemical fixation, it is often reported that the dense cores occupy a portion of the vesicle toward the center and are surrounded by a clear halo.
View Article and Find Full Text PDFJ Cell Sci
September 2024
School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Rumford St, Manchester M13 9PT, UK.
bioRxiv
April 2024
Presynaptogenesis and Intracellular Transport in Hair Cells Junior Research Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Centre Goettingen, 37075 Goettingen, Germany.
Sensory synapses are characterized by electron-dense presynaptic specializations, so-called synaptic ribbons. In cochlear inner hair cells (IHCs), ribbons play an essential role as core active zone (AZ) organizers, where they tether synaptic vesicles, cluster calcium channels and facilitate the temporally-precise release of primed vesicles. While a multitude of studies aimed to elucidate the molecular composition and function of IHC ribbon synapses, the developmental formation of these signalling complexes remains largely elusive to date.
View Article and Find Full Text PDFEur J Neurosci
May 2024
Biocenter, Theodor-Boveri-Institute, Neurobiology and Genetics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany.
The small ventrolateral neurons (sLNvs) are key components of the central clock in the Drosophila brain. They signal via the neuropeptide pigment-dispersing factor (PDF) to align the molecular clockwork of different central clock neurons and to modulate downstream circuits. The dorsal terminals of the sLNvs undergo daily morphological changes that affect presynaptic sites organised by the active zone protein Bruchpilot (BRP), a homolog of mammalian ELKS proteins.
View Article and Find Full Text PDFCurr Biol
September 2023
Department of Neuroscience, Yale School of Medicine, 295 Congress Ave, New Haven, CT 06510, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510, USA. Electronic address:
Axonal transport is key to neuronal function. Efficient transport requires specific motor-cargo association in the soma, yet the mechanisms regulating this early step remain poorly understood. We found that EBP-1, the C.
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