title: GluA1 trafficking and metabotropic NMDA: addressing results from other laboratories inconsistent with ours.
abstract: We have previously shown that when over-expressed in neurons, green fluorescent protein (GFP) tagged GluA1 (GluA1-GFP) delivery into synapses is dependent on plasticity. A recent study suggests that GluA1 over-expression leads to its incorporation into the synapse, in the absence of additional long-term potentiation-like manipulations. It is possible that a GFP tag was responsible for the difference. Using rectification index as a measure of synaptic delivery of GluA1, we found no difference in the synaptic delivery of GluA1-GFP versus untagged GluA1. We recently published a study showing that while D-APV blocks NMDAr-dependent long-term depression (LTD), MK-801 and 7-chloro kynurenate (7CK) fail to block LTD. We propose a metabotropic function for the NMDA receptor in LTD induction. In contrast to our observations, recent unpublished data suggest that the above antagonists are equally effective in blocking LTD. We noticed different methodology in their study. Here, we show that their methodology has complex effects on synaptic transmission. Therefore, it is not possible to conclude that 7CK is effective in blocking LTD from their type of experiment.
authors.affiliation: Department of Neurosciences, University of California, San Diego, , La Jolla, CA 92093, USA.
authors.forename: Sadegh
authors.initials: S
authors.lastname: Nabavi
authors.forename: Rocky
authors.initials: R
authors.lastname: Fox
authors.forename: Stephanie
authors.initials: S
authors.lastname: Alfonso
authors.forename: Jonathan
authors.initials: J
authors.lastname: Aow
authors.forename: Roberto
authors.initials: R
authors.lastname: Malinow
mesh_terms: D000818:Animals; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000378:metabolism*; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D007736:Kynurenic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D036881:Long-Term Synaptic Depression / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats; D018091:Receptors, AMPA / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D012845:Sindbis Virus; D013569:Synapses / Q000378:metabolism*; D009435:Synaptic Transmission / Q000502:physiology*
chemical_list: D049452:Green Fluorescent Proteins; D007736:Kynurenic Acid; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; C057013:7-chlorokynurenic acid
keywords: AMPA receptors; long-term depression; long-term potentiation