Abstract
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 language | English (US) |
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Pages (from-to) | 9298-9302 |
Number of pages | 5 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 92 |
Issue number | 20 |
State | Published - Sep 26 1995 |
Externally published | Yes |
Keywords
- Excitatory aniino acid receptor
- Spermidine
- Spermine
ASJC Scopus subject areas
- General
- Genetics