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Electrical Transmission among Neurons in the Buccal Ganglion of a Mollusc, Navanax inermis

The opisthobranch mollusc, Navanax, is carnivorous and cannibalistic. Prey are swallowed whole by way of a sudden expansion of the pharynx. The buccal ganglion which controls this sucking action was isolated and bathed in seawater. Attention was focused upon 10 identifiable cells visible on the gang...

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Detalles Bibliográficos
Autores principales: Levitan, H., Tauc, L., Segundo, J. P.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1970
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2203012/
https://www.ncbi.nlm.nih.gov/pubmed/4314176
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author Levitan, H.
Tauc, L.
Segundo, J. P.
author_facet Levitan, H.
Tauc, L.
Segundo, J. P.
author_sort Levitan, H.
collection PubMed
description The opisthobranch mollusc, Navanax, is carnivorous and cannibalistic. Prey are swallowed whole by way of a sudden expansion of the pharynx. The buccal ganglion which controls this sucking action was isolated and bathed in seawater. Attention was focused upon 10 identifiable cells visible on the ganglion's rostral side. Two cells were observed simultaneously, and each was penetrated with two glass microelectrodes, one for polarizing the membrane and the other for recording membrane potential variations. The coupling coefficients for direct current flow and action potentials of several identified cells were tabulated. Attenuation was essentially independent of the direction of current flow, but depended upon the relative size of the directly and indirectly polarized cells. The attenuation of subthreshold sinusoidally varying voltages increased with frequency above about 1 Hz. The coupling coefficient for spikes was lower than for DC due to greater high frequency attenuation. There is considerable similarity in the spontaneous PSP's of all cells, which is not due to the electrical coupling but to input from a common source. The 10 cells were not chemically interconnected but some were electrically connected to interneurons which fed back chemically mediated PSP's. The feedback can be negative or positive depending upon the membrane potential of the postsynaptic cell. We conclude that electrical coupling among the 10 cells plays a minor role in sudden pharyngeal contractions but that the dual electrical-chemical coupling with interneurons may be important in this respect.
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spelling pubmed-22030122008-04-23 Electrical Transmission among Neurons in the Buccal Ganglion of a Mollusc, Navanax inermis Levitan, H. Tauc, L. Segundo, J. P. J Gen Physiol Article The opisthobranch mollusc, Navanax, is carnivorous and cannibalistic. Prey are swallowed whole by way of a sudden expansion of the pharynx. The buccal ganglion which controls this sucking action was isolated and bathed in seawater. Attention was focused upon 10 identifiable cells visible on the ganglion's rostral side. Two cells were observed simultaneously, and each was penetrated with two glass microelectrodes, one for polarizing the membrane and the other for recording membrane potential variations. The coupling coefficients for direct current flow and action potentials of several identified cells were tabulated. Attenuation was essentially independent of the direction of current flow, but depended upon the relative size of the directly and indirectly polarized cells. The attenuation of subthreshold sinusoidally varying voltages increased with frequency above about 1 Hz. The coupling coefficient for spikes was lower than for DC due to greater high frequency attenuation. There is considerable similarity in the spontaneous PSP's of all cells, which is not due to the electrical coupling but to input from a common source. The 10 cells were not chemically interconnected but some were electrically connected to interneurons which fed back chemically mediated PSP's. The feedback can be negative or positive depending upon the membrane potential of the postsynaptic cell. We conclude that electrical coupling among the 10 cells plays a minor role in sudden pharyngeal contractions but that the dual electrical-chemical coupling with interneurons may be important in this respect. The Rockefeller University Press 1970-04-01 /pmc/articles/PMC2203012/ /pubmed/4314176 Text en Copyright © 1970 by The Rockefeller University Press This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Article
Levitan, H.
Tauc, L.
Segundo, J. P.
Electrical Transmission among Neurons in the Buccal Ganglion of a Mollusc, Navanax inermis
title Electrical Transmission among Neurons in the Buccal Ganglion of a Mollusc, Navanax inermis
title_full Electrical Transmission among Neurons in the Buccal Ganglion of a Mollusc, Navanax inermis
title_fullStr Electrical Transmission among Neurons in the Buccal Ganglion of a Mollusc, Navanax inermis
title_full_unstemmed Electrical Transmission among Neurons in the Buccal Ganglion of a Mollusc, Navanax inermis
title_short Electrical Transmission among Neurons in the Buccal Ganglion of a Mollusc, Navanax inermis
title_sort electrical transmission among neurons in the buccal ganglion of a mollusc, navanax inermis
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2203012/
https://www.ncbi.nlm.nih.gov/pubmed/4314176
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