Distinct NMDA receptors provide differential modes of transmission at mossy fiber-interneuron synapses.
Dentate gyrus granule cells innervate inhibitory interneurons via a continuum of synapses comprised of either Ca(2+)-impermeable (CI) or Ca(2+)-permeable (CP) AMPA receptors. Synapses at the extreme ends of this continuum engage distinct postsynaptic responses, with activity at CI synapses being strongly influenced by NMDA receptor activation. NMDARs at CI synapses have a lower NR2B subunit composition and a higher open probability, which generate larger amplitude and more rapid EPSCs than their CP counterparts. A novel form of NMDAR-dependent long-term depression (iLTD) is associated with CI-mossy fiber synapses, whereas iLTD at CP synapses is dependent on Ca(2+)-permeable AMPA receptor activation. Induction of both forms of iLTD required elevation of postsynaptic calcium. Thus mossy fibers engage CA3 interneurons via multiple synapse types that will act to expand the computational repertoire of the mossy fiber-CA3 network.
Lei
Saobo
S
Laboratory of Cellular and Molecular Neurophysiology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
McBain
Chris J
CJ
D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism; D003521:Cyclopropanes / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D005998:Glycine / Q000031:analogs & derivatives* / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology / Q000502:physiology; D066298:In Vitro Techniques; D007395:Interneurons / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D019599:Mossy Fibers, Hippocampal / Q000187:drug effects / Q000502:physiology*; D016202:N-Methylaspartate / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D010636:Phenols / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D011073:Polyamines / Q000494:pharmacology; D021122:Protein Subunits; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009435:Synaptic Transmission / Q000502:physiology*; D014633:Valine / Q000031:analogs & derivatives* / Q000494:pharmacology; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
D000927:Anticonvulsants; D002712:Chlorides; D003521:Cyclopropanes; D018691:Excitatory Amino Acid Antagonists; D010636:Phenols; D010880:Piperidines; D011073:Polyamines; D021122:Protein Subunits; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; C074003:philanthotoxin 343; C082313:2-(2,3-dicarboxycyclopropyl)glycine; D016202:N-Methylaspartate; C056639:2-amino-5-phosphopentanoic acid; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D014633:Valine; C010739:ifenprodil; D002118:Calcium; D005998:Glycine