Up-regulation of exploratory tendencies does not enhance general learning abilities in juvenile or young-adult outbred mice

General cognitive ability describes a trait that transcends specific learning domains and impacts a wide range of cognitive skills. Individual animals (including humans) exhibit wide variations in their expression of this trait. We have previously determined that the propensity for exploration is highly correlated with the general cognitive abilities of individual outbred mice. Here, we asked if inducing an increase in exploratory behaviors would causally promote an increase in animals' general learning abilities. In three experiments, juvenile and young-adult male CD-1 outbred mice were exposed to 12 novel environments starting at post-natal days 39 (juvenile) and 61 (Young adult), after which they underwent a series of cognitive and exploratory tests as adults (beginning at post-natal day 79). Exposure to novel environments promoted increases in exploration (across multiple measures) on two different tasks, including an elevated plus maze. However, a subsequent test of general learning abilities (aggregate performance across five distinct learning tasks) determined that exposure to novel environments as juveniles or young-adults had no effect on general learning abilities in adulthood. Therefore, while exposure to novel environments promotes long-lasting increases in mice's exploratory tendencies, these increases in exploration do not appear to causally impact general learning abilities. (C) 2008 Elsevier Inc. All rights reserved.