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TitleNeuronal activity remodels the F-actin based submembrane lattice in dendrites but not axons of hippocampal neurons.
Publication TypeJournal Article
Year of Publication2020
AuthorsLavoie-Cardinal, Flavie, Anthony Bilodeau, Mado Lemieux, Marc-André Gardner, Theresa Wiesner, Gabrielle Laramée, Christian Gagné, and Paul De Koninck
JournalSci Rep
Date Published2020 07 20
KeywordsActin Cytoskeleton, Actins, Animals, Animals, Newborn, Axons, Calcium, Cell Membrane, Deep Learning, Dendrites, Hippocampus, Models, Neurological, Nanostructures, Rats, Sprague-Dawley, Receptors, N-Methyl-D-Aspartate, Synapses

The nanoscale organization of the F-actin cytoskeleton in neurons comprises membrane-associated periodical rings, bundles, and longitudinal fibers. The F-actin rings have been observed predominantly in axons but only sporadically in dendrites, where fluorescence nanoscopy reveals various patterns of F-actin arranged in mixed patches. These complex dendritic F-actin patterns pose a challenge for investigating quantitatively their regulatory mechanisms. We developed here a weakly supervised deep learning segmentation approach of fluorescence nanoscopy images of F-actin in cultured hippocampal neurons. This approach enabled the quantitative assessment of F-actin remodeling, revealing the disappearance of the rings during neuronal activity in dendrites, but not in axons. The dendritic F-actin cytoskeleton of activated neurons remodeled into longitudinal fibers. We show that this activity-dependent remodeling involves [Formula: see text] and NMDA receptor-dependent mechanisms. This highly dynamic restructuring of dendritic F-actin based submembrane lattice into longitudinal fibers may serve to support activity-dependent membrane remodeling, protein trafficking and neuronal plasticity.

Alternate JournalSci Rep
PubMed ID32686703
PubMed Central IDPMC7371643
Grant List / / CIHR / Canada