title: The selective antagonism of P2X7 and P2Y1 receptors prevents synaptic failure and affects cell proliferation induced by oxygen and glucose deprivation in rat dentate gyrus.
abstract: Purinergic P2X and P2Y receptors are broadly expressed on both neurons and glial cells in the central nervous system (CNS), including dentate gyrus (DG). The aim of this research was to determine the synaptic and proliferative response of the DG to severe oxygen and glucose deprivation (OGD) in acute rat hippocampal slices and to investigate the contribution of P2X7 and P2Y1 receptor antagonism to recovery of synaptic activity after OGD. Extracellular field excitatory post-synaptic potentials (fEPSPs) in granule cells of the DG were recorded from rat hippocampal slices. Nine-min OGD elicited an irreversible loss of fEPSP and was invariably followed by the appearance of anoxic depolarization (AD). Application of MRS2179 (selective antagonist of P2Y1 receptor) and BBG (selective antagonist of P2X7 receptor), before and during OGD, prevented AD appearance and allowed a significant recovery of neurotransmission after 9-min OGD. The effects of 9-min OGD on proliferation and maturation of cells localized in the subgranular zone (SGZ) of slices prepared from rats treated with 5-Bromo-2'-deoxyuridine (BrdU) were investigated. Slices were further incubated with an immature neuron marker, doublecortin (DCX). The number of BrdU+ cells in the SGZ was significantly decreased 6 hours after OGD. This effect was antagonized by BBG, but not by MRS2179. Twenty-four hours after 9-min OGD, the number of BrdU+ cells returned to control values and a significant increase of DCX immunofluorescence was observed. This phenomenon was still evident when BBG, but not MRS2179, was applied during OGD. Furthermore, the P2Y1 antagonist reduced the number of BrdU+ cells at this time. The data demonstrate that P2X7 and P2Y1 activation contributes to early damage induced by OGD in the DG. At later stages after the insult, P2Y1 receptors might play an additional and different role in promoting cell proliferation and maturation in the DG.
authors.affiliation: Dept. of Neuroscience, Psychology, Drug Research and Child Health, NEUROFARBA, Division of Pharmacology and Toxicology, University of Florence, Florence, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Maraula
authors.affiliation: Dept. of Health Sciences, Clinical Pharmacology and Oncology Unit, University of Florence, Florence, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Lana
authors.affiliation: Dept. of Health Sciences, Clinical Pharmacology and Oncology Unit, University of Florence, Florence, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Coppi
authors.affiliation: Dept. of Neuroscience, Psychology, Drug Research and Child Health, NEUROFARBA, Division of Pharmacology and Toxicology, University of Florence, Florence, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Gentile
authors.affiliation: Dept. of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Mello
authors.affiliation: Dept. of Neuroscience, Psychology, Drug Research and Child Health, NEUROFARBA, Division of Pharmacology and Toxicology, University of Florence, Florence, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Melani
authors.affiliation: Dept. of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Galli
authors.affiliation: Dept. of Health Sciences, Clinical Pharmacology and Oncology Unit, University of Florence, Florence, Italy.
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Giovannini
authors.affiliation: Dept. of Neuroscience, Psychology, Drug Research and Child Health, NEUROFARBA, Division of Pharmacology and Toxicology, University of Florence, Florence, Italy.
authors.forename: Felicita
authors.initials: F
authors.lastname: Pedata
authors.affiliation: Dept. of Neuroscience, Psychology, Drug Research and Child Health, NEUROFARBA, Division of Pharmacology and Toxicology, University of Florence, Florence, Italy.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Pugliese
mesh_terms: D000244:Adenosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002545:Brain Ischemia / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology; D015687:Cell Hypoxia / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D018891:Dentate Gyrus / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology*; D000089662:Doublecortin Protein; D005947:Glucose / Q000172:deficiency*; D008297:Male; D058920:Purinergic P2X Receptor Antagonists / Q000494:pharmacology*; D058921:Purinergic P2Y Receptor Antagonists / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D058486:Receptors, Purinergic P2X7 / Q000378:metabolism*; D058472:Receptors, Purinergic P2Y1 / Q000378:metabolism*; D012394:Rosaniline Dyes / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects*
chemical_list: C000714848:Dcx protein, rat; D000089662:Doublecortin Protein; C111914:N(6)-methyl-2'-deoxyadenosine 3',5'-diphosphate; D058920:Purinergic P2X Receptor Antagonists; D058921:Purinergic P2Y Receptor Antagonists; D058486:Receptors, Purinergic P2X7; D058472:Receptors, Purinergic P2Y1; D012394:Rosaniline Dyes; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D005947:Glucose; C004692:coomassie Brilliant Blue