LONGITUDINAL IMPEDANCE OF THE SQUID GIANT AXON
Longitudinal alternating current impedance measurements have been made on the squid giant axon over the frequency range from 30 cycles per second to 200 kc. per second. Large sea water electrodes were used and the inter-electrode length was immersed in oil. The impedance at high frequency was appro...
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| Format: | Online |
| Language: | English |
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The Rockefeller University Press
1941
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| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2238007/ |
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pubmed-2238007 |
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pubmed-22380072008-04-23 LONGITUDINAL IMPEDANCE OF THE SQUID GIANT AXON Cole, Kenneth S. Baker, Richard F. Article Longitudinal alternating current impedance measurements have been made on the squid giant axon over the frequency range from 30 cycles per second to 200 kc. per second. Large sea water electrodes were used and the inter-electrode length was immersed in oil. The impedance at high frequency was approximately as predicted theoretically on the basis of the poorly conducting dielectric characteristics of the membrane previously determined. For the large majority of the axons, the impedance reached a maximum at a low frequency and the reactance then vanished at a frequency between 150 and 300 cycles per second. Below this frequency, the reactance was inductive, reaching a maximum and then approaching zero as the frequency was decreased. The inductive reactance is a property of the axon and requires that it contain an inductive structure. The variation of the impedance with interpolar distance indicates that the inductance is in the membrane. The impedance characteristics of the membrane as calculated from the measured longitudinal impedance of the axon may be expressed by an equivalent membrane circuit containing inductance, capacity, and resistance. For a square centimeter of membrane the capacity of 1 µf with dielectric loss is shunted by the series combination of a resistance of 400 ohms and an inductance of one-fifth henry. The Rockefeller University Press 1941-07-20 /pmc/articles/PMC2238007/ /pubmed/19873252 Text en Copyright © Copyright, 1941, by The Rockefeller Institute for Medical Research 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/). |
| repository_type |
Open Access Journal |
| institution_category |
Foreign Institution |
| institution |
US National Center for Biotechnology Information |
| building |
NCBI PubMed |
| collection |
Online Access |
| language |
English |
| format |
Online |
| author |
Cole, Kenneth S. Baker, Richard F. |
| spellingShingle |
Cole, Kenneth S. Baker, Richard F. LONGITUDINAL IMPEDANCE OF THE SQUID GIANT AXON |
| author_facet |
Cole, Kenneth S. Baker, Richard F. |
| author_sort |
Cole, Kenneth S. |
| title |
LONGITUDINAL IMPEDANCE OF THE SQUID GIANT AXON |
| title_short |
LONGITUDINAL IMPEDANCE OF THE SQUID GIANT AXON |
| title_full |
LONGITUDINAL IMPEDANCE OF THE SQUID GIANT AXON |
| title_fullStr |
LONGITUDINAL IMPEDANCE OF THE SQUID GIANT AXON |
| title_full_unstemmed |
LONGITUDINAL IMPEDANCE OF THE SQUID GIANT AXON |
| title_sort |
longitudinal impedance of the squid giant axon |
| description |
Longitudinal alternating current impedance measurements have been made on the squid giant axon over the frequency range from 30 cycles per second to 200 kc. per second. Large sea water electrodes were used and the inter-electrode length was immersed in oil. The impedance at high frequency was approximately as predicted theoretically on the basis of the poorly conducting dielectric characteristics of the membrane previously determined. For the large majority of the axons, the impedance reached a maximum at a low frequency and the reactance then vanished at a frequency between 150 and 300 cycles per second. Below this frequency, the reactance was inductive, reaching a maximum and then approaching zero as the frequency was decreased. The inductive reactance is a property of the axon and requires that it contain an inductive structure. The variation of the impedance with interpolar distance indicates that the inductance is in the membrane. The impedance characteristics of the membrane as calculated from the measured longitudinal impedance of the axon may be expressed by an equivalent membrane circuit containing inductance, capacity, and resistance. For a square centimeter of membrane the capacity of 1 µf with dielectric loss is shunted by the series combination of a resistance of 400 ohms and an inductance of one-fifth henry. |
| publisher |
The Rockefeller University Press |
| publishDate |
1941 |
| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2238007/ |
| _version_ |
1611438675407667200 |