New neurons in the dentate gyrus are involved in the expression of enhanced long‐term memory following environmental enrichment

作者：Elodie Bruel‐Jungerman, Serge Laroche, Claire Rampon · 发表于：European Journal of Neuroscience · 年份：2005 · DOI：10.1111/j.1460-9568.2005.03875.x · 被引用次数：508 · 研究领域：Neurogenesis and neuroplasticity mechanisms、Neuroinflammation and Neurodegeneration Mechanisms、Memory and Neural Mechanisms

Although thousands of new neurons are continuously produced in the dentate gyrus of rodents each day, the function of these newborn cells remains unclear. An increasing number of reports have provided correlational evidence that adult hippocampal neurogenesis is involved in learning and memory. Exposure of animals to an enriched environment leads to improvement of performance in several learning tasks and enhances neurogenesis specifically in the hippocampus. These data raise the question of whether new neurons participate in memory improvement induced by enrichment. To address this issue, we have examined whether the increase in the number of surviving adult-generated cells following environmental enrichment contributes to improved memory function. To this end, neurogenesis was substantially reduced throughout the environmental enrichment period using the antimitotic agent methylazoxymethanol acetate (MAM). Recognition memory performance of MAM-treated enriched rats was evaluated in a novel object recognition task and compared with that of naive and nontreated enriched rats. Injections of 5-bromo-2'-deoxyuridine were used to label dividing cells, together with double immunofluorescent labelling using glial or neuronal cell-specific markers. We found that enrichment led to improved long-term recognition memory and increased hippocampal neurogenesis, and that MAM treatment during environmental enrichment completely prevented both the increase in neurogenesis and enrichment-ind...