title: The effects of cocaine self-administration on dendritic spine density in the rat hippocampus are dependent on genetic background.
abstract: Chronic exposure to cocaine induces modifications to neurons in the brain regions involved in addiction. Hence, we evaluated cocaine-induced changes in the hippocampal CA1 field in Fischer 344 (F344) and Lewis (LEW) rats, 2 strains that have been widely used to study genetic predisposition to drug addiction, by combining intracellular Lucifer yellow injection with confocal microscopy reconstruction of labeled neurons. Specifically, we examined the effects of cocaine self-administration on the structure, size, and branching complexity of the apical dendrites of CA1 pyramidal neurons. In addition, we quantified spine density in the collaterals of the apical dendritic arbors of these neurons. We found differences between these strains in several morphological parameters. For example, CA1 apical dendrites were more branched and complex in LEW than in F344 rats, while the spine density in the collateral dendrites of the apical dendritic arbors was greater in F344 rats. Interestingly, cocaine self-administration in LEW rats augmented the spine density, an effect that was not observed in the F344 strain. These results reveal significant structural differences in CA1 pyramidal cells between these strains and indicate that cocaine self-administration has a distinct effect on neuron morphology in the hippocampus of rats with different genetic backgrounds.
authors: Departamento de Psicología Básica I, Facultad de Psicología, Universidad Nacional de Educación a Distancia (UNED), C/ Juan del Rosal n° 10, Madrid 28040, Spain Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid 28223, Spain.
authors: Miguel
authors: M
authors: Miguéns
authors: Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid 28223, Spain.
authors: Asta
authors: A
authors: Kastanauskaite
authors: Departamento de Psicobiología, Facultad de Psicología, UNED, Madrid 28040, Spain.
authors: Santiago M
authors: SM
authors: Coria
authors: Departamento de Psicobiología, Facultad de Psicología, UNED, Madrid 28040, Spain.
authors: Abraham
authors: A
authors: Selvas
authors: Dpto Química Inorgánica, Orgánica y Bioquímica, Facultad de Medicina de Ciudad Real, Ciudad Real 13071, Spain.
authors: Inmaculada
authors: I
authors: Ballesteros-Yañez
authors: Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid 28223, Spain Instituto Cajal (CSIC), Madrid 28002, Spain and Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Spain.
authors: Javier
authors: J
authors: DeFelipe
authors: Departamento de Psicobiología, Facultad de Psicología, UNED, Madrid 28040, Spain.
authors: Emilio
authors: E
authors: Ambrosio
mesh_terms: D000818:Animals; D056547:CA1 Region, Hippocampal / Q000187:drug effects* / Q000648:ultrastructure; D003042:Cocaine / Q000494:pharmacology*; D019970:Cocaine-Related Disorders / Q000235:genetics* / Q000473:pathology; D049229:Dendritic Spines / Q000187:drug effects* / Q000648:ultrastructure; D017966:Pyramidal Cells / Q000187:drug effects* / Q000648:ultrastructure; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D012646:Self Administration; D013045:Species Specificity
chemical_list: D003042:Cocaine
keywords: CA1; Fischer 344; Lewis; drugs of abuse; pyramidal neuron