Long-term continuous, but not daily, environmental enrichment reduces spatial memory decline in aged male mice. Neurobiol Learn Mem 2006 Mar;85(2):139-52
Date
11/01/2005Pubmed ID
16256380DOI
10.1016/j.nlm.2005.09.003Scopus ID
2-s2.0-32644469698 (requires institutional sign-in at Scopus site) 149 CitationsAbstract
Although environmental enrichment improves spatial memory and alters synaptic plasticity in aged rodents, it is unclear whether all types of enrichment treatments yield similar benefits. The present study examined the effects in aged male mice of three types of enrichment on spatial memory in Morris water maze and radial arm maze tasks, and on levels of the presynaptic protein synaptophysin in several brain regions. Non-enriched young and aged males were compared with males exposed to one of the following treatments for 10 weeks: 5 min of daily handling, 3 h of daily basic enrichment, or 24 h of continuous complex enrichment. Young controls outperformed aged controls in both tasks. Neither daily handling nor daily enrichment affected spatial memory or synaptophysin levels. In contrast, continuous enrichment significantly reduced age-related spatial memory decline in both tasks, such that this group was statistically indistinguishable from young controls in most measures of performance. Continuously enriched mice were also significantly better than other aged mice in several spatial memory measures. Despite these improvements, synaptophysin levels in the continuous enrichment group were significantly lower than those of young and aged controls in the frontoparietal cortex, hippocampus, and striatum, suggesting a negative relationship between synaptophysin levels and spatial memory in aged males. These data demonstrate that different types of enrichment in aged male mice have disparate effects on spatial memory, and that the relationship between enrichment-induced changes in synaptophysin levels and spatial memory in aged males differs from that we have previously reported in aged female mice.
Author List
Bennett JC, McRae PA, Levy LJ, Frick KMAuthor
Karyn Frick BA,MA,PhD Professor in the Psychology department at University of Wisconsin - MilwaukeeMESH terms used to index this publication - Major topics in bold
AgingAnimals
Attention
Brain
Escape Reaction
Exploratory Behavior
Male
Maze Learning
Memory
Mice
Mice, Inbred C57BL
Orientation
Reference Values
Social Environment
Synaptophysin
