title: Environmental enrichment provides a cognitive reserve to be spent in the case of brain lesion.
abstract: To experimentally verify the reserve hypothesis, the influence of rearing conditions on the cognitive performances and on dendritic spines following basal forebrain lesions was analyzed. Adult rats reared in enriched or standard conditions were depleted of the cholinergic projection to the neocortex by 192 IgG-saporin injection into Ch4 region of basal forebrain. Their performance in spatial tasks was compared with that of intact animals reared in analogous conditions. Furthermore, number and density of dendritic spines of the layer-III parietal pyramidal neurons were analyzed. Cholinergic depletion of forebrain cortex resulted in impaired performances in most behavioral tasks in animals reared in standard conditions. Conversely, the enriched lesioned animals did not exhibit most deficits evoked by cholinergic lesion, even if some deficits, such as perseverative behaviors, were still present. The pyramidal neurons exhibited an increased spine number and density in the lesioned animals reared in standard conditions. In the enriched lesioned animals, the enhancement of spine number and density elicited by the rearing condition was fully maintained but not further increased in the presence of the lesion. Thus, rearing in an enriched environment results in the development of brain and cognitive reserves that reduce the cognitive impairment following forebrain lesions.
authors.affiliation: IRCCS Santa Lucia Foundation, Rome, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Mandolesi
authors.forename: Paola
authors.initials: P
authors.lastname: De Bartolo
authors.forename: Francesca
authors.initials: F
authors.lastname: Foti
authors.forename: Francesca
authors.initials: F
authors.lastname: Gelfo
authors.forename: Francesca
authors.initials: F
authors.lastname: Federico
authors.forename: Maria Giuseppa
authors.initials: MG
authors.lastname: Leggio
authors.forename: Laura
authors.initials: L
authors.lastname: Petrosini
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000493:pharmacokinetics; D020532:Basal Nucleus of Meynert / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D001921:Brain / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology*; D018678:Cholinergic Agents / Q000493:pharmacokinetics; D002799:Cholinergic Fibers / Q000378:metabolism; D003072:Cognition Disorders / Q000175:diagnosis* / Q000378:metabolism / Q000503:physiopathology*; D004777:Environment; D006185:Habituation, Psychophysiologic; D008124:Locomotion / Q000502:physiology; D008297:Male; D018782:Maze Learning; D010812:Physical Stimulation; D016548:Prosencephalon / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D054789:Ribosome Inactivating Proteins, Type 1 / Q000493:pharmacokinetics; D000076985:Saporins; D013028:Space Perception / Q000502:physiology
chemical_list: C085696:192 IgG-saporin; D000911:Antibodies, Monoclonal; D018678:Cholinergic Agents; D054789:Ribosome Inactivating Proteins, Type 1; D000076985:Saporins