title: Evidences for a progressive microglial activation and increase in iNOS expression in rats submitted to a neurodevelopmental model of schizophrenia: reversal by clozapine.
abstract: Schizophrenia was proposed as a progressive neurodevelopmental disorder. In this regard herein we attempted to determine progressive inflammatory and oxidative alterations induced by a neonatal immune challenge and its possible reversal by clozapine administration. For this end, Wistar rats at postnatal day (PN) 5-7 were administered the viral mimetic polyriboinosinic-polyribocytidilic acid (polyI:C) or saline. A distinct group of animals additionally received the antipsychotic drug clozapine (25mg/kg) from PN60 to 74. At PN35 (periadolescence), 60 (adult) and 74 (adulthood) the animals were submitted to behavioral determinations of prepulse inhibition of the startle (PPI) and Y maze task for working memory evaluation. At PN35 and 74 the animals were sacrificed and the hippocampus (HC), prefrontal cortex (PFC) and striatum (ST) immunostained for Iba-1, a microglial marker, and inducible nitric oxide synthase (iNOS). At PN74 oxidative stress parameters, such as, reduced glutathione levels (GSH) and lipid peroxidation were determined. The results showed a progressive increase of microglial activation and iNOS immunostaining from PN35 to PN74 mainly in the CA2 and CA3 regions of the HC and in the ST. At PN74 neonatal challenge also induced an oxidative imbalance. These inflammatory alterations were accompanied by deficits in PPI and working memory only in adult life that were reversed by clozapine. Clozapine administration reversed microglial activation and iNOS increase, but not the alterations of oxidative stress parameters. Taken together these results give further evidences for a neuroprogressive etiology and course of schizophrenia and that clozapine may partly alleviate this process.
authors.affiliation: Neuropharmacology Laboratory, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil.
authors.forename: Bruna Mara Machado
authors.initials: BM
authors.lastname: Ribeiro
authors.forename: Marta Regina Santos
authors.initials: MR
authors.lastname: do Carmo
authors.forename: Rosemayre Souza
authors.initials: RS
authors.lastname: Freire
authors.forename: Nayrton Flávio Moura
authors.initials: NF
authors.lastname: Rocha
authors.forename: Vládia Célia Moreira
authors.initials: VC
authors.lastname: Borella
authors.forename: Antonio Teles
authors.initials: AT
authors.lastname: de Menezes
authors.forename: Aline Santos
authors.initials: AS
authors.lastname: Monte
authors.forename: Patrícia Xavier Lima
authors.initials: PX
authors.lastname: Gomes
authors.forename: Francisca Cléa Florenço
authors.initials: FC
authors.lastname: de Sousa
authors.forename: Mariana Lima
authors.initials: ML
authors.lastname: Vale
authors.forename: David Freitas
authors.initials: DF
authors.lastname: de Lucena
authors.forename: Clarissa Severino
authors.initials: CS
authors.lastname: Gama
authors.forename: Danielle
authors.initials: D
authors.lastname: Macêdo
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001921:Brain / Q000187:drug effects / Q000473:pathology; D003024:Clozapine / Q000627:therapeutic use*; D002658:Developmental Disabilities / Q000188:drug therapy* / Q000209:etiology*; D004195:Disease Models, Animal; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D018782:Maze Learning / Q000187:drug effects; D017628:Microglia / Q000378:metabolism / Q000473:pathology*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D011070:Poly I-C / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013216:Reflex, Startle / Q000187:drug effects; D012559:Schizophrenia / Q000139:chemically induced / Q000150:complications*
chemical_list: D014150:Antipsychotic Agents; D008315:Malondialdehyde; D052247:Nitric Oxide Synthase Type II; D003024:Clozapine; D011070:Poly I-C
keywords: Clozapine; Neonate; Neuroinflammation; Neuroprogression; PolyI:C; Schizophrenia