Interaction of sensory experience and age in spatial memory performances

During a critical period of postnatal age sensory experience has a profound effect on maturation of visual cortical wiring. Electrophysiological evidence is indicating a substantial effect of visual deprivation on the visual cortical response properties. In this study we evaluated effect of light deprivation during a limited time of postnatal age on two aspects of spatial (working and reference) memory. Light (LR) and dark (DR) reared Wistar rats at age of 40 (P40) and 60 (P60) postnatal days were trained in an open eight arm radial maze. Number of the trials required for two consequent successful navigations to reach our criterion and number of the errors within each session were assessed. During the working memory tests the P40 DR rats made performances superior to their LR counterparts. On the other hand, in the reference memory experiments the P40 LR group showed higher performances compared to their DR counterparts. While the P60 LR and DR rats appeared no difference in the maze solving for the working memory tasks both groups at P60 outperformed those at P40. Regarding the reference memory, the two groups at P40 showed superiority to those at P60. Our results suggest that the working and reference memory performances are differently influenced by the sensory deprivation and age as well.