Effect of age on the radial arm water maze-a test of spatial learning and memory.

Aged rats show decrements in performance on cognitive tasks that require the use of spatial learning and memory. We used the 8-arm radial water maze (RAWM) to measure spatial learning as a function of age in young (6 months) and old (21 months) male F344 rats. Rats were placed in the RAWM in different start arms with the same goal arm for 3 days (five trials/day); the goal arm was changed on day 4. Old rats demonstrated spatial impairment as evidenced by increased latencies to find the hidden platform on day 4. Old rats made significantly more errors, both reference and working memory errors, than young rats on all days. It is likely that the old rats utilized non-spatial strategies to solve the task, and therefore were impaired in learning a new platform location. The RAWM is a reliable, sensitive, and powerful additional test to assess age-related spatial learning and memory deficits, combining the advantages of the Morris water maze and the radial arm maze while minimizing the disadvantages.