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Electrogenic Na(+)/Ca(2+) Exchange: A Novel Amplification Step in Squid Olfactory Transduction
Olfactory receptor neurons (ORNs) from the squid, Lolliguncula brevis, respond to the odors l-glutamate or dopamine with increases in internal Ca(2+) concentrations ([Ca(2+)](i)). To directly asses the effects of increasing [Ca(2+)](i) in perforated-patched squid ORNs, we applied 10 mM caffeine to r...
Autores principales: | , |
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Formato: | Texto |
Lenguaje: | English |
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The Rockefeller University Press
2000
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2232891/ https://www.ncbi.nlm.nih.gov/pubmed/10828249 |
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author | Danaceau, Jonathan P. Lucero, Mary T. |
author_facet | Danaceau, Jonathan P. Lucero, Mary T. |
author_sort | Danaceau, Jonathan P. |
collection | PubMed |
description | Olfactory receptor neurons (ORNs) from the squid, Lolliguncula brevis, respond to the odors l-glutamate or dopamine with increases in internal Ca(2+) concentrations ([Ca(2+)](i)). To directly asses the effects of increasing [Ca(2+)](i) in perforated-patched squid ORNs, we applied 10 mM caffeine to release Ca(2+) from internal stores. We observed an inward current response to caffeine. Monovalent cation replacement of Na(+) from the external bath solution completely and selectively inhibited the caffeine-induced response, and ruled out the possibility of a Ca(2+)-dependent nonselective cation current. The strict dependence on internal Ca(2+) and external Na(+) indicated that the inward current was due to an electrogenic Na(+)/Ca(2+) exchanger. Block of the caffeine-induced current by an inhibitor of Na(+)/Ca(2+) exchange (50–100 μM 2′,4′-dichlorobenzamil) and reversibility of the exchanger current, further confirmed its presence. We tested whether Na(+)/Ca(2+) exchange contributed to odor responses by applying the aquatic odor l-glutamate in the presence and absence of 2′,4′-dichlorobenzamil. We found that electrogenic Na(+)/Ca(2+) exchange was responsible for ∼26% of the total current associated with glutamate-induced odor responses. Although Na(+)/Ca(2+) exchangers are known to be present in ORNs from numerous species, this is the first work to demonstrate amplifying contributions of the exchanger current to odor transduction. |
format | Text |
id | pubmed-2232891 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2000 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-22328912008-04-22 Electrogenic Na(+)/Ca(2+) Exchange: A Novel Amplification Step in Squid Olfactory Transduction Danaceau, Jonathan P. Lucero, Mary T. J Gen Physiol Original Article Olfactory receptor neurons (ORNs) from the squid, Lolliguncula brevis, respond to the odors l-glutamate or dopamine with increases in internal Ca(2+) concentrations ([Ca(2+)](i)). To directly asses the effects of increasing [Ca(2+)](i) in perforated-patched squid ORNs, we applied 10 mM caffeine to release Ca(2+) from internal stores. We observed an inward current response to caffeine. Monovalent cation replacement of Na(+) from the external bath solution completely and selectively inhibited the caffeine-induced response, and ruled out the possibility of a Ca(2+)-dependent nonselective cation current. The strict dependence on internal Ca(2+) and external Na(+) indicated that the inward current was due to an electrogenic Na(+)/Ca(2+) exchanger. Block of the caffeine-induced current by an inhibitor of Na(+)/Ca(2+) exchange (50–100 μM 2′,4′-dichlorobenzamil) and reversibility of the exchanger current, further confirmed its presence. We tested whether Na(+)/Ca(2+) exchange contributed to odor responses by applying the aquatic odor l-glutamate in the presence and absence of 2′,4′-dichlorobenzamil. We found that electrogenic Na(+)/Ca(2+) exchange was responsible for ∼26% of the total current associated with glutamate-induced odor responses. Although Na(+)/Ca(2+) exchangers are known to be present in ORNs from numerous species, this is the first work to demonstrate amplifying contributions of the exchanger current to odor transduction. The Rockefeller University Press 2000-06-01 /pmc/articles/PMC2232891/ /pubmed/10828249 Text en © 2000 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 | Original Article Danaceau, Jonathan P. Lucero, Mary T. Electrogenic Na(+)/Ca(2+) Exchange: A Novel Amplification Step in Squid Olfactory Transduction |
title | Electrogenic Na(+)/Ca(2+) Exchange: A Novel Amplification Step in Squid Olfactory Transduction |
title_full | Electrogenic Na(+)/Ca(2+) Exchange: A Novel Amplification Step in Squid Olfactory Transduction |
title_fullStr | Electrogenic Na(+)/Ca(2+) Exchange: A Novel Amplification Step in Squid Olfactory Transduction |
title_full_unstemmed | Electrogenic Na(+)/Ca(2+) Exchange: A Novel Amplification Step in Squid Olfactory Transduction |
title_short | Electrogenic Na(+)/Ca(2+) Exchange: A Novel Amplification Step in Squid Olfactory Transduction |
title_sort | electrogenic na(+)/ca(2+) exchange: a novel amplification step in squid olfactory transduction |
topic | Original Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2232891/ https://www.ncbi.nlm.nih.gov/pubmed/10828249 |
work_keys_str_mv | AT danaceaujonathanp electrogenicnaca2exchangeanovelamplificationstepinsquidolfactorytransduction AT luceromaryt electrogenicnaca2exchangeanovelamplificationstepinsquidolfactorytransduction |