title: Fear-related behaviors in Lurcher mutant mice exposed to a predator.
abstract: The Lurcher mutant mice are characterized by massive cerebellar cortex degeneration. Besides their motor and cognitive disturbances, they exhibit both exaggerated blood corticosterone (CORT) level surge and behavioral disinhibition when confronted to anxiogenic conditions (i.e. to a potential threat). In this study, we assessed if such physiological and behavioral hyperactivity was also detectable in a fear-eliciting situation (actual threat). For this purpose, the behaviors and CORT level elevations in Lurcher mice were compared with those of littermate controls in the predator exposure test: mice were exposed either to a rat (exposure) or to a brief wave of the experimenter's hand (sham exposure). While the basal CORT concentrations (24 h before testing) were not significantly different between mice of both genotypes, the post-exposure ones were higher in Lurcher than in control mice whatever the condition of the experimental design (exposure or sham exposure). Predator exposure did not provoke significant increase of CORT levels whatever the genotype. On the contrary, our data clearly showed that fear-related behaviors of cerebellar mutants facing a real threat were exacerbated in comparison to those of control mice. These results suggest that the cerebellar cortex not only participates to fear conditioning and anxiety but also actively contributes to the modulation of the innate fear-related behaviors.
authors.affiliation: Laboratoire de Psychologie et Neurosciences de la Cognition et de l'Affectivité, EA4700, Université de Rouen, LARC Neurosciences Network, Mont-Saint-Aignan Cedex; Institut de Pharmacologie Moléculaire et Cellulaire IPMC, UMR7275 CNRS, Université de Nice - Sophia-Antipolis, Equipe "Développement de stratégies thérapeutiques innovantes pour le traitement de la dépression et de l'AVC", Valbonne; Centre d'Etudes des Transformations des Activités Physiques et Sportives, EA 3832, Université de Rouen, Mont-Saint-Aignan Cedex, France.
authors.forename: T
authors.initials: T
authors.lastname: Lorivel
authors.forename: V
authors.initials: V
authors.lastname: Roy
authors.forename: P
authors.initials: P
authors.lastname: Hilber
mesh_terms: D000818:Animals; D001007:Anxiety / Q000097:blood / Q000235:genetics*; D001522:Behavior, Animal / Q000502:physiology*; D002526:Cerebellar Diseases / Q000097:blood / Q000235:genetics*; D003345:Corticosterone / Q000097:blood*; D005239:Fear / Q000502:physiology*; D005260:Female; D008297:Male; D051379:Mice; D008818:Mice, Neurologic Mutants; D051381:Rats
chemical_list: D003345:Corticosterone
keywords: Cerebellum; Lurcher; corticosterone; fear; predator