title: Long-term depression of kainate receptor-mediated synaptic transmission.
abstract: Kainate receptors (KARs) have been shown to be involved in hippocampal mossy fiber long-term potentiation (LTP); however, it is not known if KARs are involved in the induction or expression of long-term depression (LTD), the other major form of long-term synaptic plasticity. Here we describe LTD of KAR-mediated synaptic transmission (EPSC(KA) LTD) in perirhinal cortex layer II/III neurons that is distinct from LTD of AMPAR-mediated transmission, which also coexists at the same synapses. Induction of EPSC(KA) LTD requires a rise in postsynaptic Ca(2+) but is independent of NMDARs or T-type voltage-gated Ca(2+) channels; however, it requires synaptic activation of inwardly rectifying KARs and release of Ca(2+) from stores. The synaptic KARs are regulated by tonically activated mGluR5, and expression of EPSC(KA) LTD occurs via a mechanism involving mGluR5, PKC, and PICK1 PDZ domain interactions. Thus, we describe the induction and expression mechanism of a form of synaptic plasticity, EPSC(KA) LTD.
authors.affiliation: Biomedical Science, School of Medicine and Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
authors.forename: Yunkyung
authors.initials: Y
authors.lastname: Park
authors.forename: Jihoon
authors.initials: J
authors.lastname: Jo
authors.forename: John T R
authors.initials: JT
authors.lastname: Isaac
authors.forename: Kwangwook
authors.initials: K
authors.lastname: Cho
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology; D003598:Cytoskeletal Proteins; D018728:Entorhinal Cortex / Q000502:physiology*; D066298:In Vitro Techniques; D036881:Long-Term Synaptic Depression; D009474:Neurons / Q000502:physiology; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology; D009994:Osmolar Concentration; D011493:Protein Kinase C / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D064529:Receptor, Metabotropic Glutamate 5; D018092:Kainic Acid Receptors / Q000502:physiology*; D018094:Receptors, Metabotropic Glutamate / Q000502:physiology; D013569:Synapses / Q000378:metabolism; D009435:Synaptic Transmission / Q000502:physiology*
chemical_list: D002118:Calcium; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D009687:Nuclear Proteins; D011493:Protein Kinase C; D064529:Receptor, Metabotropic Glutamate 5; D018092:Kainic Acid Receptors; D018094:Receptors, Metabotropic Glutamate; C578937:Grm5 protein, rat; C498298:PICK1 protein, rat