title: Behavioral Biomarkers of Schizophrenia in High Drinker Rats: A Potential Endophenotype of Compulsive Neuropsychiatric Disorders.
abstract: Psychogenic polydipsia, which is compulsive, non-regulatory fluid consumption, is present in 6%-20% of chronic psychiatric patients and frequently associated with the schizophrenia diagnosis. In the present study, we investigated the relation between schizophrenia-like symptoms and biomarkers with a compulsive drinking behavior phenotype in rats. Rats that were selected for low drinking vs high drinking behavior following schedule-induced polydipsia (SIP) were assessed in a latent inhibition (LI) paradigm using tone and electrical foot shock and in a spatial reversal learning task to evaluate behavioral inflexibility. We also analyzed the myelin basic protein in different brain areas of high drinker (HD) and low drinker (LD) rats. The HD rats, which were characterized by a compulsive drinking behavior on SIP, had a reduced level of LI effect and increased behavioral inflexibility in the spatial reversal learning task in comparison to the LD group. Moreover, HD rats showed less myelination in the center of the corpus callosum, striatum, and amygdala in comparison to LD rats. These findings strengthen the validity of HD rats that were selected by SIP as a possible phenotype of compulsive neuropsychiatric disorders, as evidenced by the existence of behaviors and biological markers that are related to schizophrenia and obsessive-compulsive disorder, including a reduced LI effect, behavioral inflexibility and reduced brain myelination. Future studies could contribute to the elucidation of the mechanisms underlying the compulsive phenotype of HD rats and its relation to vulnerability to schizophrenia.
authors.affiliation: Department of Psychology, University of Almería, Campus de Excelencia Internacional Agroalimentario (CEIA3), Almería, Spain.
authors.forename: Silvia V
authors.initials: SV
authors.lastname: Navarro
authors.affiliation: Department of Psychology, University of Almería, Campus de Excelencia Internacional Agroalimentario (CEIA3), Almería, Spain.
authors.forename: Roberto
authors.initials: R
authors.lastname: Alvarez
authors.affiliation: Department of Psychology and Research Center for Behavior Assessment (CRAMC), Universitat Rovira i Virgili, Tarragona, Spain.|Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira i Virgili, Tarragona, Spain.
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Colomina
authors.affiliation: Department of Psychology, University of Almería, Campus de Excelencia Internacional Agroalimentario (CEIA3), Almería, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Sanchez-Santed
authors.affiliation: Department of Psychology, University of Almería, Campus de Excelencia Internacional Agroalimentario (CEIA3), Almería, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Flores
authors.affiliation: Department of Psychology, University of Almería, Campus de Excelencia Internacional Agroalimentario (CEIA3), Almería, Spain.
authors.forename: Margarita
authors.initials: M
authors.lastname: Moreno
mesh_terms: D000679:Amygdala / Q000473:pathology*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D015415:Biomarkers; D003192:Compulsive Behavior / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology*; D003337:Corpus Callosum / Q000473:pathology*; D003342:Corpus Striatum / Q000473:pathology*; D004195:Disease Models, Animal; D004327:Drinking Behavior / Q000502:physiology; D058068:Endophenotypes; D007266:Inhibition, Psychological; D051381:Rats; D017208:Rats, Wistar; D012193:Reversal Learning / Q000502:physiology; D012559:Schizophrenia / Q000150:complications / Q000473:pathology* / Q000503:physiopathology*
chemical_list: D015415:Biomarkers
keywords: compulsivity; latent inhibition; myelination; reversal learning; schedule-induced polydipsia; schizophrenia