Short communicationExposure to an enriched environment up to middle age allows preservation of spatial memory capabilities in old age

•Environmental enrichment until middle age preserves spatial memory of aged rats.•Enrichment until middle-age is as efficient as whole adult life enrichment to preserve spatial memory of aged rats.•Enrichment from middle age only mitigates age-related spatial memory decline.

In rats, some cognitive capabilities, like spatial learning and memory, are preserved from age-related decline by whole adult life enriched environment (EE) exposure. However, to which extent late EE contributes to such maintenance remains to be investigated. Here we assessed the impact of late housing condition (e.g., from the age of 18 months) on spatial learning and memory of aged rats (24 months) previously exposed or unexposed to EE from young adulthood. The results showed that late EE was not required for spatial memory maintenance in aged rats previously housed in EE. In contrast, late EE mitigates spatial memory deficit in aged rats previously unexposed to EE. These outcomes suggest that EE exposure up to middle age provides a “reserve”-like advantage which supports an enduring preservation of spatial capabilities in old age.