title: Late enrichment maintains accurate recent and remote spatial memory only in aged rats that were unimpaired when middle aged.
abstract: Exposure of rodents to a stimulating environment has beneficial effects on some cognitive functions that are impaired during physiological aging, and especially spatial reference memory. The present study investigated whether environmental enrichment rescues these functions in already declining subjects and/or protects them from subsequent decline. Subgroups of 17-mo-old female rats with unimpaired versus impaired performance in a spatial reference memory task (Morris water maze) were housed until the age of 24 mo in standard or enriched environment. They were then trained in a second reference memory task, conducted in a different room than the first, and recent (1 d) and remote (10 d) memory were assessed. In unimpaired subgroups, spatial memory declined from 17 to 24 mo in rats housed in standard conditions; an enriched environment during this period allowed maintenance of accurate recent and remote spatial memory. At 24 mo, rats impaired at the age of 17 mo housed in enriched environment learned the task and displayed substantial recent memory, but their performance remained lower than that of unimpaired rats, showing that enrichment failed to rescue spatial memory in already cognitively declining rats. Controls indicated carryover effects of the first water maze training, especially in aged rats housed in standard condition, and confirmed the beneficial effect of enrichment on remote memory of aged rats even if they performed poorly than young adults housed for the same duration in standard or enriched condition.
authors.affiliation: Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Unistra, Neuropôle de Strasbourg, Faculté de Psychologie, 67000 Strasbourg, France Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, CNRS, GDR 2905, 67000 Strasbourg, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: Fuchs
authors.affiliation: Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Unistra, Neuropôle de Strasbourg, Faculté de Psychologie, 67000 Strasbourg, France Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, CNRS, GDR 2905, 67000 Strasbourg, France.
authors.forename: Karine
authors.initials: K
authors.lastname: Herbeaux
authors.affiliation: Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Unistra, Neuropôle de Strasbourg, Faculté de Psychologie, 67000 Strasbourg, France Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, CNRS, GDR 2905, 67000 Strasbourg, France.
authors.forename: Noémie
authors.initials: N
authors.lastname: Aufrere
authors.affiliation: Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Unistra, Neuropôle de Strasbourg, Faculté de Psychologie, 67000 Strasbourg, France Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, CNRS, GDR 2905, 67000 Strasbourg, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Kelche
authors.affiliation: Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Unistra, Neuropôle de Strasbourg, Faculté de Psychologie, 67000 Strasbourg, France Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, CNRS, GDR 2905, 67000 Strasbourg, France.
authors.forename: Chantal
authors.initials: C
authors.lastname: Mathis
authors.affiliation: Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Unistra, Neuropôle de Strasbourg, Faculté de Psychologie, 67000 Strasbourg, France Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, CNRS, GDR 2905, 67000 Strasbourg, France.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Barbelivien
authors.affiliation: Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Unistra, Neuropôle de Strasbourg, Faculté de Psychologie, 67000 Strasbourg, France Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, CNRS, GDR 2905, 67000 Strasbourg, France majchrza@unistra.fr.
authors.forename: Monique
authors.initials: M
authors.lastname: Majchrzak
mesh_terms: D000375:Aging; D000818:Animals; D004777:Environment; D005260:Female; D057567:Memory, Long-Term; D020318:Rats, Long-Evans; D065852:Spatial Memory