title: Involvement of the infralimbic cortex and CA1 hippocampal area in reconsolidation of a contextual fear memory through CB1 receptors: Effects of CP55,940.
abstract: The endocannabinoid system (ECS) has a pivotal role in different cognitive functions such as learning and memory. Recent evidence confirm the involvement of the hippocampal CB1 receptors in the modulation of both memory extinction and reconsolidation processes in different brain areas, but few studies focused on the infralimbic cortex, another important cognitive area. Here, we infused the cannabinoid agonist CP55,940 either into the infralimbic cortex (IL) or the CA1 area of the dorsal hippocampus (HPC) of adult male Wistar rats immediately after a short (3min) reactivation session, known to labilize a previously consolidated memory trace in order to allow its reconsolidation with some modification. In both structures, the treatment was able to disrupt reconsolidation in a relatively long lasting way, reducing the freezing response. To our notice, this is the first demonstration of ECS involvement in reconsolidation in the Infralimbic Cortex. Despite poorly discriminative between CB1 and CB2 receptors, CP55,940 is a potent agent, and these results suggest that a similar CB1-dependent circuitry is at work both in HPC and in the IL during memory reconsolidation.
authors.affiliation: Psychobiology and Neurocomputing Lab, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Neuroscience, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Fabiana
authors.initials: F
authors.lastname: Santana
authors.affiliation: Psychobiology and Neurocomputing Lab, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Neuroscience, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Rodrigo O
authors.initials: RO
authors.lastname: Sierra
authors.affiliation: Psychobiology and Neurocomputing Lab, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Neuroscience, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Josué
authors.initials: J
authors.lastname: Haubrich
authors.affiliation: Psychobiology and Neurocomputing Lab, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Neuroscience, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Crestani
authors.affiliation: Psychobiology and Neurocomputing Lab, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Neuroscience, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Johanna Marcela
authors.initials: JM
authors.lastname: Duran
authors.affiliation: Psychobiology and Neurocomputing Lab, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Neuroscience, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Lindsey
authors.initials: L
authors.lastname: de Freitas Cassini
authors.affiliation: Neurobiology of Memory Lab, Biophysics Department, Biosciences Institute, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Neuroscience, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Lucas
authors.initials: L
authors.lastname: de Oliveira Alvares
authors.affiliation: Psychobiology and Neurocomputing Lab, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Neuroscience, Institute of Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil. Electronic address: quillfe@ufrgs.br.
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Quillfeldt
mesh_terms: D000818:Animals; D056547:CA1 Region, Hippocampal / Q000187:drug effects / Q000502:physiology*; D003511:Cyclohexanols / Q000008:administration & dosage*; D005239:Fear / Q000187:drug effects / Q000502:physiology*; D008297:Male; D000069077:Memory Consolidation / Q000187:drug effects / Q000502:physiology*; D017397:Prefrontal Cortex / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D043884:Receptor, Cannabinoid, CB1 / Q000819:agonists / Q000502:physiology*
chemical_list: D003511:Cyclohexanols; D043884:Receptor, Cannabinoid, CB1; C054649:3-(2-hydroxy-4-(1,1-dimethylheptyl)phenyl)-4-(3-hydroxypropyl)cyclohexanol
keywords: CP55,940; Contextual fear conditioning; Hippocampus CA1 area; Infralimbic cortex; Memory reconsolidation