Enhanced functional detection of synaptic calcium-permeable AMPA receptors using intracellular NASPM
Calcium-permeable AMPA-type glutamate receptors (CP-AMPARs) contribute to many forms of synaptic plasticity and pathology. They can be distinguished from GluA2-containing calcium-impermeable AMPARs by the inward rectification of their currents, which reflects voltage-dependent channel block by intra...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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eLife Sciences Publications Ltd
2023-04-01
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| Series: | eLife |
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| Online Access: | https://elifesciences.org/articles/66765 |
| _version_ | 1797830355642744832 |
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| author | Ian Coombs Cécile Bats Craig A Sexton Dorota Studniarczyk Stuart G Cull-Candy Mark Farrant |
| author_facet | Ian Coombs Cécile Bats Craig A Sexton Dorota Studniarczyk Stuart G Cull-Candy Mark Farrant |
| author_sort | Ian Coombs |
| collection | DOAJ |
| description | Calcium-permeable AMPA-type glutamate receptors (CP-AMPARs) contribute to many forms of synaptic plasticity and pathology. They can be distinguished from GluA2-containing calcium-impermeable AMPARs by the inward rectification of their currents, which reflects voltage-dependent channel block by intracellular spermine. However, the efficacy of this weakly permeant blocker is differentially altered by the presence of AMPAR auxiliary subunits – including transmembrane AMPAR regulatory proteins, cornichons, and GSG1L – which are widely expressed in neurons and glia. This complicates the interpretation of rectification as a measure of CP-AMPAR expression. Here, we show that the inclusion of the spider toxin analog 1-naphthylacetyl spermine (NASPM) in the intracellular solution results in a complete block of GluA1-mediated outward currents irrespective of the type of associated auxiliary subunit. In neurons from GluA2-knockout mice expressing only CP-AMPARs, intracellular NASPM, unlike spermine, completely blocks outward synaptic currents. Thus, our results identify a functional measure of CP-AMPARs, that is unaffected by their auxiliary subunit content. |
| first_indexed | 2024-04-09T13:34:56Z |
| format | Article |
| id | doaj.art-49f9a89f7bef4f0c803556abfb71db58 |
| institution | Directory Open Access Journal |
| issn | 2050-084X |
| language | English |
| last_indexed | 2024-04-09T13:34:56Z |
| publishDate | 2023-04-01 |
| publisher | eLife Sciences Publications Ltd |
| record_format | Article |
| series | eLife |
| spelling | doaj.art-49f9a89f7bef4f0c803556abfb71db582023-05-09T12:55:14ZengeLife Sciences Publications LtdeLife2050-084X2023-04-011210.7554/eLife.66765Enhanced functional detection of synaptic calcium-permeable AMPA receptors using intracellular NASPMIan Coombs0https://orcid.org/0000-0003-1006-7471Cécile Bats1https://orcid.org/0000-0002-2246-7248Craig A Sexton2https://orcid.org/0000-0002-7617-8361Dorota Studniarczyk3https://orcid.org/0000-0003-4109-7956Stuart G Cull-Candy4https://orcid.org/0000-0002-0831-8326Mark Farrant5https://orcid.org/0000-0002-9918-0376Department of Neuroscience, Physiology and Pharmacology, University College London, London, United KingdomDepartment of Neuroscience, Physiology and Pharmacology, University College London, London, United KingdomDepartment of Neuroscience, Physiology and Pharmacology, University College London, London, United KingdomDepartment of Neuroscience, Physiology and Pharmacology, University College London, London, United KingdomDepartment of Neuroscience, Physiology and Pharmacology, University College London, London, United KingdomDepartment of Neuroscience, Physiology and Pharmacology, University College London, London, United KingdomCalcium-permeable AMPA-type glutamate receptors (CP-AMPARs) contribute to many forms of synaptic plasticity and pathology. They can be distinguished from GluA2-containing calcium-impermeable AMPARs by the inward rectification of their currents, which reflects voltage-dependent channel block by intracellular spermine. However, the efficacy of this weakly permeant blocker is differentially altered by the presence of AMPAR auxiliary subunits – including transmembrane AMPAR regulatory proteins, cornichons, and GSG1L – which are widely expressed in neurons and glia. This complicates the interpretation of rectification as a measure of CP-AMPAR expression. Here, we show that the inclusion of the spider toxin analog 1-naphthylacetyl spermine (NASPM) in the intracellular solution results in a complete block of GluA1-mediated outward currents irrespective of the type of associated auxiliary subunit. In neurons from GluA2-knockout mice expressing only CP-AMPARs, intracellular NASPM, unlike spermine, completely blocks outward synaptic currents. Thus, our results identify a functional measure of CP-AMPARs, that is unaffected by their auxiliary subunit content.https://elifesciences.org/articles/66765AMPA-type glutamate receptorexcitatory postsynaptic currentTARPspermineNASPMrectification |
| spellingShingle | Ian Coombs Cécile Bats Craig A Sexton Dorota Studniarczyk Stuart G Cull-Candy Mark Farrant Enhanced functional detection of synaptic calcium-permeable AMPA receptors using intracellular NASPM eLife AMPA-type glutamate receptor excitatory postsynaptic current TARP spermine NASPM rectification |
| title | Enhanced functional detection of synaptic calcium-permeable AMPA receptors using intracellular NASPM |
| title_full | Enhanced functional detection of synaptic calcium-permeable AMPA receptors using intracellular NASPM |
| title_fullStr | Enhanced functional detection of synaptic calcium-permeable AMPA receptors using intracellular NASPM |
| title_full_unstemmed | Enhanced functional detection of synaptic calcium-permeable AMPA receptors using intracellular NASPM |
| title_short | Enhanced functional detection of synaptic calcium-permeable AMPA receptors using intracellular NASPM |
| title_sort | enhanced functional detection of synaptic calcium permeable ampa receptors using intracellular naspm |
| topic | AMPA-type glutamate receptor excitatory postsynaptic current TARP spermine NASPM rectification |
| url | https://elifesciences.org/articles/66765 |
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