PSYCHOMOTOR AND SPATIAL MEMORY PERFORMANCE IN AGING MALE FISCHER-344 RATS

Psychomotor and spatial memory performance were examined in male Fisch er 344 rats that were 6, 12, 15, 18, and 22 months of age, to assess t hese parameters as a function of age and to determine at what age thes e behaviors begin to deteriorate. Complex motor behaviors, as measured by rod walk, wire suspension, plank walk, inclined screen, and accele rating rotarod performance, declined steadily with age, with most meas ures being adversely affected as early as 12 to 15 months of age. Spat ial learning and memory performance, as measured by the working memory version of the Morris water maze (MWM), showed decrements at 18 and 2 2 months of age (higher latencies on the working memory trial), with s ome change noticeable as early as 12-15 months of age (no improvement on the second trial following a IO-min retention interval); these diff erences were not due to swim speed. Therefore, complex motor and spati al memory behaviors show noticeable declines early in the lifespan of the male Fisher 344 rat. This cross-sectional age analysis study using the latest behavioral techniques determines the minimal age at which psychomotor and spatial learning and memory behaviors deteriorate; thi s information is important when planning for longitudinal studies wher e interventions are tested for their efficacy in preventing or restori ng age-related behavioral deficits. Published by Elsevier Science Inc.