Subunit-dependent postsynaptic expression of kainate receptors on hippocampal interneurons in area CA1.
Kainate receptors (KARs) contribute to postsynaptic excitation in only a select subset of neurons. To define the parameters that specify the postsynaptic expression of KARs, we examined the contribution of KARs to EPSCs on hippocampal interneurons in area CA1. Interneurons in stratum radiatum/lacunosum-moleculare express KARs both with and without the GluR5 subunit, but KAR-mediated EPSCs are generated mainly, if not entirely, by GluR5-containing KARs. Extrasynaptic glutamate spillover profoundly recruits AMPA receptors (AMPARs) with little effect on KARs, indicating that KARs are targeted at the synapse more precisely than AMPARs. However, spontaneous EPSCs with a conventional AMPAR component did not have a resolvable contribution of KARs, suggesting that the KARs that contribute to the evoked EPSCs are at a distinct set of synapses. GluR5-containing KARs on interneurons in stratum oriens do not contribute substantially to the EPSC. We conclude that KARs are localized to synapses by cell type-, synapse-, and subunit-selective mechanisms.
Wondolowski
Joyce
J
Department of Behavioral Neuroscience and Neuroscience Graduate Program, Oregon Health & Science University, Beaverton, Oregon 97006, USA.
Frerking
Matthew
M
D000409:Alanine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001224:Aspartic Acid / Q000494:pharmacology; D001418:Baclofen / Q000494:pharmacology; D001581:Benzothiadiazines / Q000494:pharmacology; D001703:Biophysics; D004558:Electric Stimulation / Q000379:methods; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology*; D018755:GABA Agonists / Q000494:pharmacology; D038983:Galactolipids / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology*; D066298:In Vitro Techniques; D007395:Interneurons / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D018092:Kainic Acid Receptors / Q000819:agonists / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D013941:Thymine / Q000031:analogs & derivatives / Q000494:pharmacology; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
D000409:Alanine; D001224:Aspartic Acid; D001418:Baclofen; D001581:Benzothiadiazines; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D018755:GABA Agonists; D038983:Galactolipids; D018092:Kainic Acid Receptors; D013941:Thymine; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; C509618:1-(2-amino-2-carboxyethyl)-3-(2-carboxybenzyl)pyrimidine-2,4-dione; C120673:benzyloxyaspartate; C475298:diacylgalactosylglycerol; C004639:cyclothiazide