Introgression of Brown Norway chromosome 13 improves visual spatial memory in the Dahl S rat

The present study was conducted in an effort to evaluate whether chromosomal substitution can repair impaired exploration learning and memory. It has previously been observed that Dahl salt-sensitive (SS) rodents exhibit impaired cognitive function along with abnormal physiological responses to muscle stimulation. Introgression of Brown Norway chromosome (13(BN)) has been found to restore normal physiological processes in SS animals. However, the effect of chromosomal substitution on cognitive performance has not been explored. It was hypothesized that 13(BN) also rescues cognitive impairments in these animals. Visual spatial learning and cognitive flexibility were evaluated using the Morris water maze (MWM) and the T-maze. This manipulation is effective in rescuing impaired task acquisition, but not perseveration observed in the SS animal. These animals may represent a natural animal model in which to isolate genetic information responsible for learning and memory function.