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In vivo assembly of the axon initial segment in motor neurons
The axon initial segment (AIS) is responsible for both the modulation of action potentials and the maintenance of neuronal polarity. Yet, the molecular mechanisms controlling its assembly are incompletely understood. Our study in single electroporated motor neurons in mouse embryos revealed that Ank...
Autores principales: | , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Springer Berlin Heidelberg
2013
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4072062/ https://www.ncbi.nlm.nih.gov/pubmed/23728480 http://dx.doi.org/10.1007/s00429-013-0578-7 |
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author | Le Bras, Barbara Fréal, Amélie Czarnecki, Antonny Legendre, Pascal Bullier, Erika Komada, Masayuki Brophy, Peter J. Davenne, Marc Couraud, François |
author_facet | Le Bras, Barbara Fréal, Amélie Czarnecki, Antonny Legendre, Pascal Bullier, Erika Komada, Masayuki Brophy, Peter J. Davenne, Marc Couraud, François |
author_sort | Le Bras, Barbara |
collection | PubMed |
description | The axon initial segment (AIS) is responsible for both the modulation of action potentials and the maintenance of neuronal polarity. Yet, the molecular mechanisms controlling its assembly are incompletely understood. Our study in single electroporated motor neurons in mouse embryos revealed that AnkyrinG (AnkG), the AIS master organizer, is undetectable in bipolar migrating motor neurons, but is already expressed at the beginning of axonogenesis at E9.5 and initially distributed homogeneously along the entire growing axon. Then, from E11.5, a stage when AnkG is already apposed to the membrane, as observed by electron microscopy, the protein progressively becomes restricted to the proximal axon. Analysis on the global motor neurons population indicated that Neurofascin follows an identical spatio-temporal distribution, whereas sodium channels and β4-spectrin only appear along AnkG(+) segments at E11.5. Early patch-clamp recordings of individual motor neurons indicated that at E12.5 these nascent AISs are already able to generate spikes. Using knock-out mice, we demonstrated that neither β4-spectrin nor Neurofascin control the distal-to-proximal restriction of AnkG. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00429-013-0578-7) contains supplementary material, which is available to authorized users. |
format | Online Article Text |
id | pubmed-4072062 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2013 |
publisher | Springer Berlin Heidelberg |
record_format | MEDLINE/PubMed |
spelling | pubmed-40720622014-07-18 In vivo assembly of the axon initial segment in motor neurons Le Bras, Barbara Fréal, Amélie Czarnecki, Antonny Legendre, Pascal Bullier, Erika Komada, Masayuki Brophy, Peter J. Davenne, Marc Couraud, François Brain Struct Funct Original Article The axon initial segment (AIS) is responsible for both the modulation of action potentials and the maintenance of neuronal polarity. Yet, the molecular mechanisms controlling its assembly are incompletely understood. Our study in single electroporated motor neurons in mouse embryos revealed that AnkyrinG (AnkG), the AIS master organizer, is undetectable in bipolar migrating motor neurons, but is already expressed at the beginning of axonogenesis at E9.5 and initially distributed homogeneously along the entire growing axon. Then, from E11.5, a stage when AnkG is already apposed to the membrane, as observed by electron microscopy, the protein progressively becomes restricted to the proximal axon. Analysis on the global motor neurons population indicated that Neurofascin follows an identical spatio-temporal distribution, whereas sodium channels and β4-spectrin only appear along AnkG(+) segments at E11.5. Early patch-clamp recordings of individual motor neurons indicated that at E12.5 these nascent AISs are already able to generate spikes. Using knock-out mice, we demonstrated that neither β4-spectrin nor Neurofascin control the distal-to-proximal restriction of AnkG. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00429-013-0578-7) contains supplementary material, which is available to authorized users. Springer Berlin Heidelberg 2013-06-02 2014 /pmc/articles/PMC4072062/ /pubmed/23728480 http://dx.doi.org/10.1007/s00429-013-0578-7 Text en © The Author(s) 2013 https://creativecommons.org/licenses/by/2.0/ Open AccessThis article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited. |
spellingShingle | Original Article Le Bras, Barbara Fréal, Amélie Czarnecki, Antonny Legendre, Pascal Bullier, Erika Komada, Masayuki Brophy, Peter J. Davenne, Marc Couraud, François In vivo assembly of the axon initial segment in motor neurons |
title | In vivo assembly of the axon initial segment in motor neurons |
title_full | In vivo assembly of the axon initial segment in motor neurons |
title_fullStr | In vivo assembly of the axon initial segment in motor neurons |
title_full_unstemmed | In vivo assembly of the axon initial segment in motor neurons |
title_short | In vivo assembly of the axon initial segment in motor neurons |
title_sort | in vivo assembly of the axon initial segment in motor neurons |
topic | Original Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4072062/ https://www.ncbi.nlm.nih.gov/pubmed/23728480 http://dx.doi.org/10.1007/s00429-013-0578-7 |
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