Intracellular polyamines mediate inward rectification of Ca2+-permeable α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors

Sean D. Donevan, Michael A Rogawski

Research output: Contribution to journalArticlepeer-review

189 Scopus citations


α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors that lack the glutamate receptor GluR2 subunit are Ca2+-permeable and exhibit inwardly rectifying current responses to kainate and AMPA. A proportion of cultured rat hippocampal neurons show similar Ca2+-permeable inwardly rectifying AMPA receptor currents. Inward rectification in these neurons was lost with intracellular dialysis and was not present in excised outside-out patches but was maintained in perforated-patch whole-cell recordings, suggesting that a diffusible cytoplasmic factor may be responsible for rectification. Inclusion of the naturally occurring polyamines spermine and spermidine in the recording pipette prevented loss of rectification in both whole-cell and excisedpatch recordings; Mg2+ and putrescine were without effect. Inward rectification of Ca2+-permeable AMPA receptors may reflect voltage-dependent channel block by intracellular polyamines.

Original languageEnglish (US)
Pages (from-to)9298-9302
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number20
StatePublished - Sep 26 1995
Externally publishedYes


  • Excitatory aniino acid receptor
  • Spermidine
  • Spermine

ASJC Scopus subject areas

  • General
  • Genetics


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