Long-term retention of spatial navigation by preweanling rats

The present study was designed to examine retention of spatial information in the immature, Fischer-344N rat using a savings paradigm. Following training to locate a hidden platform using extramaze cues, preweanling animals (17 days of age) were immediately probed by testing in the tank with the platform removed. One week later, pups (26 days of age) were given all additional four training trials immediately followed by a second probe test to examine the animals' memory for the location of the platform. Animals that received initial training at 17 days of age demonstrated significant savings of information when tested after the retention interval. These data replicate our recent report of spatial navigation capabilities in the preweanling rat, and extend those findings by demonstrating that preweanling spatial navigation performance permits more rapid and accurate navigation following a 7-day retention interval after a "reinstatement" insufficient to produce accurate navigation in maturation controls. (C) 2002 John Wiley & Sons, Inc.