title: Synaptic kainate receptors in interplay with INaP shift the sparse firing of dentate granule cells to a sustained rhythmic mode in temporal lobe epilepsy.
abstract: Dentate granule cells, at the gate of the hippocampus, use coincidence detection of synaptic inputs to code afferent information under a sparse firing regime. In both human patients and animal models of temporal lobe epilepsy, mossy fibers sprout to form an aberrant glutamatergic network between dentate granule cells. These new synapses operate via long-lasting kainate receptor-mediated events, which are not present in the naive condition. Here, we report that in chronic epileptic rat, aberrant kainate receptors in interplay with the persistent sodium current dramatically expand the temporal window for synaptic integration. This introduces a multiplicative gain change in the input-output operation of dentate granule cells. As a result, their sparse firing is switched to an abnormal sustained and rhythmic mode. We conclude that synaptic kainate receptors dramatically alter the fundamental coding properties of dentate granule cells in temporal lobe epilepsy.
authors.affiliation: Inserm Unité 901, Marseille 13009, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Artinian
authors.forename: Angélique
authors.initials: A
authors.lastname: Peret
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Marti
authors.forename: Jérôme
authors.initials: J
authors.lastname: Epsztein
authors.forename: Valérie
authors.initials: V
authors.lastname: Crépel
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D001703:Biophysics; D018891:Dentate Gyrus / Q000473:pathology*; D004195:Disease Models, Animal; D004558:Electric Stimulation; D004833:Epilepsy, Temporal Lobe / Q000473:pathology*; D018683:Excitatory Amino Acid Agents / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques / Q000379:methods; D051381:Rats; D017208:Rats, Wistar; D018092:Kainic Acid Receptors / Q000378:metabolism*; D026941:Sodium Channel Blockers / Q000494:pharmacology; D015222:Sodium Channels / Q000502:physiology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology
chemical_list: D018683:Excitatory Amino Acid Agents; D018092:Kainic Acid Receptors; D026941:Sodium Channel Blockers; D015222:Sodium Channels; D013779:Tetrodotoxin