title: Synaptic kainate receptors in CA1 interneurons gate the threshold of theta-frequency-induced long-term potentiation.
abstract: Theta oscillations (4-12 Hz) in neuronal networks are known to predispose the synapses involved to plastic changes and may underlie their association with learning behaviors. The lowered threshold for synaptic plasticity during theta oscillations is thought to be due to decreased GABAergic inhibition. Interneuronal kainate receptors (KARs) regulate GABAergic transmission and are implicated in theta activity; however, the physiological significance of this regulation is unknown. In rat hippocampus, we show that during theta activity, there is excitatory postsynaptic drive to CA1 interneurons mediated by KARs. This promotes feedforward inhibition of pyramidal neurons, raising the threshold for induction of theta-burst long-term potentiation. These results identify a novel mechanism whereby the activation of postsynaptic KARs in CA1 interneurons gate changes in synaptic efficacy to a physiologically relevant patterned stimulation.
authors.affiliation: Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland. vernon.clarke@helsinki.fi
authors.forename: Vernon R J
authors.initials: VR
authors.lastname: Clarke
authors.forename: Graham L
authors.initials: GL
authors.lastname: Collingridge
authors.forename: Sari E
authors.initials: SE
authors.lastname: Lauri
authors.forename: Tomi
authors.initials: T
authors.lastname: Taira
mesh_terms: D000818:Animals; D056547:CA1 Region, Hippocampal / Q000378:metabolism; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology*; D005260:Female; D007395:Interneurons / Q000378:metabolism*; D017774:Long-Term Potentiation / Q000502:physiology*; D008297:Male; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D018092:Kainic Acid Receptors / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism*
chemical_list: D018092:Kainic Acid Receptors