Identification of the Kainate Receptor Subunits Underlying Modulation of Excitatory Synaptic Transmission in the CA3 Region of the Hippocampus
Open Access
- 15 November 2000
- journal article
- Published by Society for Neuroscience in Journal of Neuroscience
- Vol. 20 (22), 8269-8278
- https://doi.org/10.1523/jneurosci.20-22-08269.2000
Abstract
To understand the physiological role of kainate receptors and their participation in seizure induction in animal models of epilepsy, it will be necessary to develop a comprehensive description of their action in the CA3 region of the hippocampus. Activation of presynaptic kainate receptors depresses excitatory synaptic transmission at mossy fiber and associational-commissural inputs to CA3 pyramidal neurons (Vignes et al., 1998; Bortolotto et al., 1999; Kamiya and Ozawa, 2000). In this study, we use gene-targeted mice lacking glutamate receptor 5 (GluR5) or GluR6 kainate receptor subunits to identify the receptor subunits that comprise the kainate receptors responsible for presynaptic modulation of CA3 transmission. We found that bath application of kainate (3 μm) profoundly reduced EPSCs at mossy fiber and collateral synapses in neurons from wild-type and GluR5−/−mice but had no effect on EPSCs in neurons from GluR6−/−mice. These results therefore contrast with previous studies that supported a role for GluR5-containing receptors at mossy fiber and associational-commissural synapses (Vignes et al., 1998; Bortolotto et al., 1999). Surprisingly, at perforant path synapses kainate receptor activation enhanced transmission; this potentiation was abolished in both GluR5 and GluR6 knock-out mice. Kainate receptors thus play multiple and complex roles to modulate excitatory synaptic transmission in the CA3 region of the hippocampus.Keywords
This publication has 33 references indexed in Scilit:
- Synaptic kainate receptorsCurrent Opinion in Neurobiology, 2000
- Kainate receptor‐mediated presynaptic inhibition at the mouse hippocampal mossy fibre synapseThe Journal of Physiology, 2000
- The GluR5 subtype of kainate receptor regulates excitatory synaptic transmission in areas CA1 and CA3 of the rat hippocampusNeuropharmacology, 1998
- Kainate receptor‐mediated inhibition of presynaptic Ca2+ influx and EPSP in area CA1 of the rat hippocampusThe Journal of Physiology, 1998
- Regulation of glutamate release by presynaptic kainate receptors in the hippocampusNature, 1996
- Cloned Glutamate ReceptorsAnnual Review of Neuroscience, 1994
- Comparison of Two Forms of Long-Term Potentiation in Single Hippocampal NeuronsScience, 1990
- The three-dimensional organization of the hippocampal formation: A review of anatomical dataNeuroscience, 1989
- Limbic seizure and brain damage produced by kainic acid: Mechanisms and relevance to human temporal lobe epilepsyNeuroscience, 1985
- Topographic organization of the projections from the entorhinal area to the hippocampal formation of the ratJournal of Comparative Neurology, 1976