title: Differential neuronal plasticity in mouse hippocampus associated with various periods of enriched environment during postnatal development.
abstract: Enriched environment (EE) is characterized by improved conditions for enhanced exploration, cognitive activity, social interaction and physical exercise. It has been shown that EE positively regulates the remodeling of neural circuits, memory consolidation, long-term changes in synaptic strength and neurogenesis. However, the fine mechanisms by which environment shapes the brain at different postnatal developmental stages and the duration required to induce such changes are still a matter of debate. In EE, large groups of mice were housed in bigger cages and were given toys, nesting materials and other equipment that promote physical activity to provide a stimulating environment. Weaned mice were housed in EE for 4, 6 or 8 weeks and compared with matched control mice that were raised in a standard environment. To investigate the differential effects of EE on immature and mature brains, we also housed young adult mice (8 weeks old) for 4 weeks in EE. We studied the influence of onset and duration of EE housing on the structure and function of hippocampal neurons. We found that: (1) EE enhances neurogenesis in juvenile, but not young adult mice; (2) EE increases the number of synaptic contacts at every stage; (3) long-term potentiation (LTP) and spontaneous and miniature activity at the glutamatergic synapses are affected differently by EE depending on its onset and duration. Our study provides an integrative view of the role of EE during postnatal development in various mechanisms of plasticity in the hippocampus including neurogenesis, synaptic morphology and electrophysiological parameters of synaptic connectivity. This work provides an explanation for discrepancies found in the literature about the effects of EE on LTP and emphasizes the importance of environment on hippocampal plasticity.
authors.affiliation: Université de Nice Sophia Antipolis, 06103, Nice, France.|Centre National de La Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, 660 Route Des Lucioles, 06560, Valbonne, France.
authors.forename: Salma
authors.initials: S
authors.lastname: Hosseiny
authors.affiliation: Université de Nice Sophia Antipolis, 06103, Nice, France.|Centre National de La Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, 660 Route Des Lucioles, 06560, Valbonne, France.
authors.forename: Mariel
authors.initials: M
authors.lastname: Pietri
authors.affiliation: Université de Nice Sophia Antipolis, 06103, Nice, France.|Centre National de La Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, 660 Route Des Lucioles, 06560, Valbonne, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Petit-Paitel
authors.affiliation: Université de Nice Sophia Antipolis, 06103, Nice, France.|Centre National de La Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, 660 Route Des Lucioles, 06560, Valbonne, France.
authors.forename: Hadi
authors.initials: H
authors.lastname: Zarif
authors.affiliation: Université de Nice Sophia Antipolis, 06103, Nice, France.|Centre National de La Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, 660 Route Des Lucioles, 06560, Valbonne, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Heurteaux
authors.affiliation: Université de Nice Sophia Antipolis, 06103, Nice, France.|Centre National de La Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, 660 Route Des Lucioles, 06560, Valbonne, France.
authors.forename: Joëlle
authors.initials: J
authors.lastname: Chabry
authors.affiliation: Université de Nice Sophia Antipolis, 06103, Nice, France. alice.guyon@ipmc.cnrs.fr.|Centre National de La Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, 660 Route Des Lucioles, 06560, Valbonne, France. alice.guyon@ipmc.cnrs.fr.
authors.forename: Alice
authors.initials: A
authors.lastname: Guyon
mesh_terms: D000818:Animals; D049229:Dendritic Spines; D004777:Environment; D019706:Excitatory Postsynaptic Potentials; D005260:Female; D006624:Hippocampus / Q000254:growth & development* / Q000502:physiology*; D017774:Long-Term Potentiation; D051379:Mice; D008810:Mice, Inbred C57BL; D055369:Miniature Postsynaptic Potentials; D055495:Neurogenesis; D017966:Pyramidal Cells / Q000502:physiology*
keywords: Enriched environment; Excitatory postsynaptic currents; Hippocampus neurogenesis and synaptogenesis; Long-term potentiation; Postnatal development