title: Layer-specific potentiation of network GABAergic inhibition in the CA1 area of the hippocampus.
abstract: One of the most important functions of GABAergic inhibition in cortical regions is the tight control of spatiotemporal activity of principal neuronal ensembles. However, electrophysiological recordings do not provide sufficient spatial information to determine the spatiotemporal properties of inhibitory plasticity. Using Voltage Sensitive Dye Imaging (VSDI) in mouse hippocampal slices, we demonstrate that GABAA-mediated field inhibitory postsynaptic potentials undergo layer-specific potentiation upon activation of metabotropic glutamate receptors (mGlu). VSDI recordings allowed detection of pharmacologically isolated GABAA-dependent hyperpolarization signals. Bath-application of the selective group-I mGlu receptor agonist, (S)-3,5-Dihydroxyphenylglycine (DHPG), induces an enhancement of the GABAergic VSDI-recorded signal, which is more or less pronounced in different hippocampal layers. This potentiation is mediated by mGlu5 and downstream activation of IP3 receptors. Our results depict network GABAergic activity in the hippocampal CA1 region and its sub-layers, showing also a novel form of inhibitory synaptic plasticity tightly coupled to glutamatergic activity.
authors.affiliation: INSERM U1215, NeuroCentre Magendie, AVENIR Group "Endocannabinoids and Neuroadaptation", 33077 Bordeaux, France.|Université de Bordeaux, 33077 Bordeaux, France.|University of Catania, Biometec - Department of Biomedical and Biotechnological Sciences, 95125 Catania, Italy.
authors.forename: Michelangelo
authors.initials: M
authors.lastname: Colavita
authors.affiliation: INSERM U1215, NeuroCentre Magendie, AVENIR Group "Endocannabinoids and Neuroadaptation", 33077 Bordeaux, France.|Université de Bordeaux, 33077 Bordeaux, France.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Terral
authors.affiliation: INSERM U1215, NeuroCentre Magendie, AVENIR Group "Endocannabinoids and Neuroadaptation", 33077 Bordeaux, France.|Université de Bordeaux, 33077 Bordeaux, France.
authors.forename: Clement E
authors.initials: CE
authors.lastname: Lemercier
authors.affiliation: University of Catania, Biometec - Department of Biomedical and Biotechnological Sciences, 95125 Catania, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Drago
authors.affiliation: INSERM U1215, NeuroCentre Magendie, AVENIR Group "Endocannabinoids and Neuroadaptation", 33077 Bordeaux, France.|Université de Bordeaux, 33077 Bordeaux, France.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Marsicano
authors.affiliation: INSERM U1215, NeuroCentre Magendie, AVENIR Group "Endocannabinoids and Neuroadaptation", 33077 Bordeaux, France.|Université de Bordeaux, 33077 Bordeaux, France.
authors.forename: Federico
authors.initials: F
authors.lastname: Massa
mesh_terms: D000818:Animals; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology; D066298:In Vitro Techniques; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018408:Patch-Clamp Techniques; D011963:Receptors, GABA-A / Q000737:chemistry / Q000378:metabolism; D018094:Receptors, Metabotropic Glutamate / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012118:Resorcinols / Q000494:pharmacology; D055366:Synaptic Potentials / Q000187:drug effects
chemical_list: D053496:Inositol 1,4,5-Trisphosphate Receptors; D011963:Receptors, GABA-A; D018094:Receptors, Metabotropic Glutamate; D012118:Resorcinols; C079215:3,5-dihydroxyphenylglycine; D005998:Glycine