title: Differential Involvement of the Dentate Gyrus in Adaptive Forgetting in the Rat.
abstract: How does the brain discriminate essential information aimed to be stored permanently from information required only temporarily, and that needs to be cleared away for not saturating our precious memory space? Reference Memory (RM) refers to the long-term storage of invariable information whereas Working Memory (WM) depends on the short-term storage of trial-unique information. Previous work has revealed that WM tasks are very sensitive to proactive interference. In order to prevent such interference, irrelevant old memories must be forgotten to give new ones the opportunity to be stabilized. However, unlike memory, physiological processes underlying this adaptive form of forgetting are still poorly understood. Here, we precisely ask what specific brain structure(s) could be responsible for such process to occur. To answer this question, we trained rats in a radial maze using three paradigms, a RM task and two WM tasks involving or not the processing of interference but strictly identical in terms of locomotion or motivation. We showed that an inhibition of the expression of Zif268 and c-Fos, two indirect markers of neuronal activity and synaptic plasticity, was observed in the dentate gyrus of the dorsal hippocampus when processing such interfering previously stored information. Conversely, we showed that inactivating the dentate gyrus impairs both RM and WM, but improves the processing of interference. Altogether, these results strongly suggest for the first time that the dentate gyrus could be a key structure involved in adaptive forgetting.
authors.affiliation: University Lyon 1, University Lyon 1, Lyon, France.
authors.forename: Mickaël Antoine
authors.initials: MA
authors.lastname: Joseph
authors.affiliation: University Lyon 1, University Lyon 1, Lyon, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Fraize
authors.affiliation: University Lyon 1, University Lyon 1, Lyon, France.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Ansoud-Lerouge
authors.affiliation: University Lyon 1, University Lyon 1, Lyon, France; Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5292, Lyon, France; Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1028, Lyon, France; Lyon Neuroscience Research Center (CRNL), Lyon, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Sapin
authors.affiliation: University Lyon 1, University Lyon 1, Lyon, France; Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5292, Lyon, France; Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1028, Lyon, France; Lyon Neuroscience Research Center (CRNL), Lyon, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Peyron
authors.affiliation: University Lyon 1, University Lyon 1, Lyon, France; Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5292, Lyon, France; Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1028, Lyon, France; Lyon Neuroscience Research Center (CRNL), Lyon, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Arthaud
authors.affiliation: University Lyon 1, University Lyon 1, Lyon, France; Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5292, Lyon, France; Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1028, Lyon, France; Lyon Neuroscience Research Center (CRNL), Lyon, France.
authors.forename: Paul-Antoine
authors.initials: PA
authors.lastname: Libourel
authors.affiliation: University Lyon 1, University Lyon 1, Lyon, France; Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5292, Lyon, France; Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1028, Lyon, France; Lyon Neuroscience Research Center (CRNL), Lyon, France.
authors.forename: Régis
authors.initials: R
authors.lastname: Parmentier
authors.affiliation: University Lyon 1, University Lyon 1, Lyon, France; Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5292, Lyon, France; Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1028, Lyon, France; Lyon Neuroscience Research Center (CRNL), Lyon, France.
authors.forename: Paul Antoine
authors.initials: PA
authors.lastname: Salin
authors.affiliation: University Lyon 1, University Lyon 1, Lyon, France; Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5292, Lyon, France; Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1028, Lyon, France; Lyon Neuroscience Research Center (CRNL), Lyon, France.
authors.forename: Gaël
authors.initials: G
authors.lastname: Malleret
mesh_terms: D000223:Adaptation, Psychological / Q000502:physiology*; D000818:Animals; D018891:Dentate Gyrus / Q000502:physiology*; D051766:Early Growth Response Protein 1 / Q000096:biosynthesis; D005786:Gene Expression Regulation / Q000502:physiology; D008570:Memory, Short-Term / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis; D051381:Rats
chemical_list: D051766:Early Growth Response Protein 1; C486110:Egr1 protein, rat; D016760:Proto-Oncogene Proteins c-fos