Enhanced functional detection of synaptic calcium-permeable AMPA receptors using intracellular NASPM.
Enhanced functional detection of synaptic calcium-permeable AMPA receptors using intracellular NASPM.
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DOI：
10.7554/elife.66765
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发表时间：
2023-04-12
期刊：
影响因子：
7.7
通讯作者：
Farrant M
中科院分区：
文献类型：
--
作者：
Coombs I;Bats C;Sexton CA;Studniarczyk D;Cull-Candy SG;Farrant M
钙渗透性AMPA型谷氨酸受体（CP-AMPAR）有助于许多形式的突触可塑性和病理学。它们可以通过其电流的向内整流与含GluA 2的钙不可渗透的AMPAR区分开来，这反映了细胞内精胺的电压依赖性通道阻滞。然而，这种弱渗透性阻滞剂的功效因AMPAR辅助亚基的存在而发生差异性改变-包括跨膜AMPAR调节蛋白，cornichons和GSG 1 L-它们广泛表达于神经元和神经胶质细胞中。这使得将校正解释为CP-AMPAR表达的量度变得复杂。在这里，我们表明，列入蜘蛛毒素类似物1-naphthylacetyl精胺（NASPM）在细胞内的解决方案的结果在一个完整的块GluA 1介导的外向电流，无论相关的辅助亚基的类型。在来自仅表达CP-AMPAR的GluA 2敲除小鼠的神经元中，细胞内NASPM与精胺不同，完全阻断外向突触电流。因此，我们的研究结果确定了CP-AMPAR的功能措施，这是不受其辅助亚基含量。
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.