title: Rats with differential self-grooming expression in the elevated plus-maze do not differ in anxiety-related behaviors.
abstract: Individual differences are important biological predictors for reactivity to stressful stimulation. The extent to which trait differences underlie animal's reactions to conditioned and unconditioned fear stimuli, for example, is still to be clarified. Although grooming behavior has been associated with some aspects of the obsessive-compulsive disorder in humans, its relation with other anxiety disorders is still unknown. Given that grooming behavior could be a component of the whole spectrum of these disorders, in the present study we allocated male Wistar rats in low, intermediate and high self-grooming groups according to the duration of such behavior in the elevated plus-maze (EPM). These groups were then evaluated in unconditioned fear tests, such as the EPM and the open-field, and in conditioned fear tests, such as fear-potentiated startle and fear extinction retention. Additionally, we studied the expression of unconditioned behaviors in marble burying test and the sensorimotor gate function with prepulse inhibition test. Neurochemicals and neuroendocrine parameters were also evaluated, with the quantification of basal corticosterone in the plasma, and dopamine, serotonin and their metabolites in brain structures involved with fear processing. In general, rats classified according to grooming expression showed similar performance in all behavioral tests. Accordingly, corticosterone and monoamine concentrations were similar among groups. Thus, despite grooming expression elicited by different approaches--especially pharmacological ones--has been related with some aspects of anxiety disorders, rats with different expression of spontaneous self-grooming in the EPM do not differ in anxiety-like behaviors nor in neurochemical and neuroendocrine parameters generally associated with anxiety disorders.
authors.affiliation: Laboratório de Neuropsicofarmacologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil; Instituto de Neurociências e Comportamento, Ribeirão Preto, Brazil. Electronic address: aereimer@usp.br.
authors.forename: Adriano Edgar
authors.initials: AE
authors.lastname: Reimer
authors.affiliation: Instituto de Neurociências e Comportamento, Ribeirão Preto, Brazil; Grupo de Psicobiologia, Centro de Educação e Ciências Humanas, Universidade Federal de São Carlos, São Carlos, Brazil.
authors.forename: Amanda Ribeiro
authors.initials: AR
authors.lastname: de Oliveira
authors.affiliation: Departamento de Psiquiatria, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Juliana Belo
authors.initials: JB
authors.lastname: Diniz
authors.affiliation: Departamento de Psiquiatria, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Marcelo Queiroz
authors.initials: MQ
authors.lastname: Hoexter
authors.affiliation: Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Silvana
authors.initials: S
authors.lastname: Chiavegatto
authors.affiliation: Laboratório de Neuropsicofarmacologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil; Instituto de Neurociências e Comportamento, Ribeirão Preto, Brazil.
authors.forename: Marcus Lira
authors.initials: ML
authors.lastname: Brandão
mesh_terms: D000818:Animals; D001007:Anxiety; D003192:Compulsive Behavior; D003214:Conditioning, Classical; D005239:Fear; D006120:Grooming; D007206:Individuality; D008297:Male; D051381:Rats; D017208:Rats, Wistar
keywords: Anxiety-like behaviors; Conditioned fear; Individual differences; Obsessive-compulsive disorder; Unconditioned fear