title: Nano Secondary Ion Mass Spectrometry Imaging of Dopamine Distribution Across Nanometer Vesicles.
abstract: We report an approach to spatially resolve the content across nanometer neuroendocrine vesicles in nerve-like cells by correlating super high-resolution mass spectrometry imaging, NanoSIMS, with transmission electron microscopy (TEM). Furthermore, intracellular electrochemical cytometry at nanotip electrodes is used to count the number of molecules in individual vesicles to compare to imaged amounts in vesicles. Correlation between the NanoSIMS and TEM provides nanometer resolution of the inner structure of these organelles. Moreover, correlation with electrochemical methods provides a means to quantify and relate vesicle neurotransmitter content and release, which is used to explain the slow transfer of dopamine between vesicular compartments. These nanoanalytical tools reveal that dopamine loading/unloading between vesicular compartments, dense core and halo solution, is a kinetically limited process. The combination of NanoSIMS and TEM has been used to show the distribution profile of newly synthesized dopamine across individual vesicles. Our findings suggest that the vesicle inner morphology might regulate the neurotransmitter release event during open and closed exocytosis from dense core vesicles with hours of equilibrium needed to move significant amounts of catecholamine from the protein dense core despite its nanometer size.
authors.affiliation: Department of Chemistry and Chemical Engineering, Chalmers University of Technology , Gothenburg SE-412 96, Sweden.|National Centre for Imaging Mass Spectrometry, Chalmers University of Technology and University of Gothenburg , Gothenburg SE-412 96, Sweden.
authors.forename: Jelena
authors.initials: J
authors.lastname: Lovrić
authors.affiliation: Department of Chemistry and Chemical Engineering, Chalmers University of Technology , Gothenburg SE-412 96, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Dunevall
authors.affiliation: Department of Chemistry and Molecular Biology, University of Gothenburg , Gothenburg SE-412 96, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Larsson
authors.affiliation: Department of Chemistry and Chemical Engineering, Chalmers University of Technology , Gothenburg SE-412 96, Sweden.
authors.forename: Lin
authors.initials: L
authors.lastname: Ren
authors.affiliation: Cardiovascular and Metabolic Diseases, Innovative Medicines and Early Development Biotech Unit, AstraZeneca , Mölndal SE-431 50, Sweden.
authors.forename: Shalini
authors.initials: S
authors.lastname: Andersson
authors.affiliation: Laboratory for Biological Geochemistry, École Polytechnique Fédérale de Lausanne and Center for Advanced Surface Analysis, Institute of Earth Sciences, University of Lausanne , Lausanne CH-1015, Switzerland.
authors.forename: Anders
authors.initials: A
authors.lastname: Meibom
authors.affiliation: Department of Chemistry and Chemical Engineering, Chalmers University of Technology , Gothenburg SE-412 96, Sweden.|National Centre for Imaging Mass Spectrometry, Chalmers University of Technology and University of Gothenburg , Gothenburg SE-412 96, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Malmberg
authors.affiliation: Cardiovascular and Metabolic Diseases, Innovative Medicines and Early Development Biotech Unit, AstraZeneca , Mölndal SE-431 50, Sweden.
authors.forename: Michael E
authors.identifier: 0000-0001-6579-9691
authors.initials: ME
authors.lastname: Kurczy
authors.affiliation: Department of Chemistry and Chemical Engineering, Chalmers University of Technology , Gothenburg SE-412 96, Sweden.|National Centre for Imaging Mass Spectrometry, Chalmers University of Technology and University of Gothenburg , Gothenburg SE-412 96, Sweden.|Department of Chemistry and Molecular Biology, University of Gothenburg , Gothenburg SE-412 96, Sweden.
authors.forename: Andrew G
authors.identifier: 0000-0002-2084-0133
authors.initials: AG
authors.lastname: Ewing
mesh_terms: D000818:Animals; D002395:Catecholamines / Q000737:chemistry / Q000302:isolation & purification; D004298:Dopamine / Q000032:analysis*; D004337:Drug Carriers / Q000737:chemistry; D004566:Electrodes; D005089:Exocytosis; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology; D018377:Neurotransmitter Agents / Q000737:chemistry / Q000378:metabolism; D016716:PC12 Cells; D010316:Particle Size; D051381:Rats; D018629:Spectrometry, Mass, Secondary Ion; D013499:Surface Properties
chemical_list: D002395:Catecholamines; D004337:Drug Carriers; D018377:Neurotransmitter Agents; D004298:Dopamine
keywords: NanoSIMS; electrochemistry; nanocompartments; nanoimaging; vesicle content