title: The consolidation of inhibitory avoidance memory in mice depends on the intensity of the aversive stimulus: The involvement of the amygdala, dorsal hippocampus and medial prefrontal cortex.
abstract: Several studies using inhibitory avoidance models have demonstrated the importance of limbic structures, such as the amygdala, dorsal hippocampus and medial prefrontal cortex, in the consolidation of emotional memory. However, we aimed to investigate the role of the amygdala (AMG), dorsal hippocampus (DH) and medial prefrontal cortex (mPFC) of mice in the consolidation of step-down inhibitory avoidance and whether this avoidance would be conditioned relative to the intensity of the aversive stimulus. To test this, we bilaterally infused anisomycin (ANI-40μg/μl, a protein synthesis inhibitor) into one of these three brain areas in mice. These mice were then exposed to one of two different intensities (moderate: 0.5mA or intense: 1.5mA) in a step-down inhibitory avoidance task. We found that consolidation of both of the aversive experiences was mPFC dependent, while the AMG and DH were only required for the consolidation of the intense experience. We suggest that in moderately aversive situations, which do not represent a severe physical risk to the individual, the consolidation of aversive experiences does not depend on protein synthesis in the AMG or the DH, but only the mPFC. However, for intense aversive stimuli all three of these limbic structures are essential for the consolidation of the experience.
authors: Laboratório de Neurociências, Departamento de Fisioterapia, Centro de Ciências Biológicas e Saúde, Universidade Federal de São Carlos, Rod. Washington Luis, Km 235, 13565-905 São Carlos, Brazil; Programa de Pós-Graduação em Psicobiologia, Universidade de São Paulo, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Departamento de Psicologia, Avenida Bandeirantes, 3900, Monte Alegre, CEP 14040-901, Ribeirão Preto, SP, Brazil; INeC, Instituto de Neurociências e Comportamento, Avenida Bandeirantes, 3900, CEP 14040-901, Monte Alegre, Ribeirão Preto, SP, Brazil. Electronic address: lucascanto@gmail.com.
authors: L
authors: L
authors: Canto-de-Souza
authors: Laboratório de Neurociências, Departamento de Fisioterapia, Centro de Ciências Biológicas e Saúde, Universidade Federal de São Carlos, Rod. Washington Luis, Km 235, 13565-905 São Carlos, Brazil; Programa de Pós-Graduação em Psicobiologia, Universidade de São Paulo, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Departamento de Psicologia, Avenida Bandeirantes, 3900, Monte Alegre, CEP 14040-901, Ribeirão Preto, SP, Brazil. Electronic address: mattioli@ufscar.br.
authors: R
authors: R
authors: Mattioli
mesh_terms: D000679:Amygdala / Q000187:drug effects*; D000818:Animals; D000841:Anisomycin / Q000494:pharmacology; D001362:Avoidance Learning / Q000187:drug effects*; D004597:Electroshock; D004644:Emotions / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects*; D008297:Male; D008568:Memory / Q000187:drug effects*; D051379:Mice; D017397:Prefrontal Cortex / Q000187:drug effects*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology
chemical_list: D011500:Protein Synthesis Inhibitors; D000841:Anisomycin
keywords: Amygdala; Anisomycin; Dorsal hippocampus; Emotional memory; Medial prefrontal cortex; Mice