Environmental enrichment provides a cognitive reserve to be spent in the case of brain lesion.
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.
Mandolesi
Laura
L
IRCCS Santa Lucia Foundation, Rome, Italy.
De Bartolo
Paola
P
Foti
Francesca
F
Gelfo
Francesca
F
Federico
Francesca
F
Leggio
Maria Giuseppa
MG
Petrosini
Laura
L
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
C085696:192 IgG-saporin; D000911:Antibodies, Monoclonal; D018678:Cholinergic Agents; D054789:Ribosome Inactivating Proteins, Type 1; D000076985:Saporins