Depression of GABAergic input to identified hippocampal neurons by group III metabotropic glutamate receptors in the rat
| Autor: | Yannis Dalezios, Francesco Ferraguti, Ryuichi Shigemoto, Marco Capogna, Peter Somogyi, Naoki Kogo |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Patch-Clamp Techniques
Time Factors Xanthenes/pharmacology Cell Count Cell Count/methods Membrane Potentials/drug effects Hippocampal formation Receptors Metabotropic Glutamate Hippocampus Membrane Potentials Horseradish Peroxidase/metabolism Immunohistochemistry/methods Drug Interactions Amino Acids 2-Amino-5-phosphonovalerate/pharmacology gamma-Aminobutyric Acid/metabolism Microscopy Immunoelectron Horseradish Peroxidase gamma-Aminobutyric Acid Lysine/analogs & derivatives Synapses/drug effects Chemistry Pyramidal Cells General Neuroscience musculoskeletal neural and ocular physiology Microscopy Immunoelectron/methods Long-term potentiation Immunohistochemistry medicine.anatomical_structure Amino Acids/pharmacology Hippocampus/cytology GABAergic Interneurons/classification Somatostatin Presynaptic active zone Interneuron In Vitro Techniques Neurotransmission Inhibitory postsynaptic potential Neural Inhibition/drug effects Statistics Nonparametric Interneurons medicine Animals Pyramidal Cells/drug effects Rats Wistar Somatostatin/metabolism Dose-Response Relationship Drug Lysine Neural Inhibition Receptors Metabotropic Glutamate/agonists Rats Excitatory Amino Acid Antagonists/pharmacology 2-Amino-5-phosphonovalerate Xanthenes Animals Newborn nervous system Metabotropic glutamate receptor Synapses sense organs Propionates Excitatory Amino Acid Antagonists Neuroscience Propionates/pharmacology |
| Zdroj: | Kogo, N, Dalezios, Y, Capogna, M, Ferraguti, F, Shigemoto, R & Somogyi, P 2004, ' Depression of GABAergic input to identified hippocampal neurons by group III metabotropic glutamate receptors in the rat ', The European journal of neuroscience, vol. 19, no. 10, pp. 2727-40 . https://doi.org/10.1111/j.0953-816X.2004.03394.x |
| DOI: | 10.1111/j.0953-816X.2004.03394.x |
| Popis: | The release of GABA in synapses is modulated by presynaptic metabotropic glutamate receptors (mGluRs). We tested whether GABA release to identified hippocampal neurons is influenced by group III mGluR activation using the agonist L-(+)-2-amino-4-phosphonobutyric acid (L-AP4) on inhibitory postsynaptic currents (IPSCs) evoked in CA1 interneurons and pyramidal cells. In interneurons, characterized with biocytin and immunolabelling for somatostatin, evoked IPSCs were depressed by 50 micro m L-AP4 (activating mGluR4 and 8) to 68 +/- 6% of control, but they were rarely depressed in pyramidal cells (96 +/- 4% of control). At 300-500 micro m concentration (activating mGluR4, 7 and 8), L-AP4 depressed IPSCs in both interneurons (to 70 +/- 6%) and pyramidal cells (to 67 +/- 4%). The change in trial-to-trial variability and in paired-pulse depression indicated a presynaptic action. In interneurons, the degree of IPSC depression was variable (to 9-87%), and a third of IPSCs were not affected by L-AP4. The L-AP4-evoked IPSC depression was blocked by LY341495. The depression of IPSCs was similar in O-LM cells and other interneurons. The lack of cell-type selectivity and the similar efficacy of different concentrations of L-AP4 suggest that several group III mGluRs are involved in the depression of IPSCs. Electron microscopic immunocytochemistry confirmed that mGluR4, mGluR7a and mGluR8a occur in the presynaptic active zone of GABAergic terminals on interneurons, but not on those innervating pyramidal cells. The high variability of L-AP4-evoked IPSC suppression is in line with the selective expression of presynaptic mGluRs by several distinct types of GABAergic neuron innervating each interneuron type. |
| Databáze: | OpenAIRE |
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