SPATIAL-LEARNING IN MALE AND FEMALE LONG-EVANS RATS

Male and female Long-Evans rats were tested in the Morris water maze a t 6 months of age. A place training procedure, in which rats learned t he position of a camouflaged platform, was followed by cue training, i n which rats escaped to a visible platform. No sex difference was foun d in place learning ability. Search accuracy on probe trials, when the platform was unavailable, was also equivalent for the male and female groups. These results contrast with previous studies of rodents at yo unger ages, which have reported a male advantage in spatial learning. It is suggested that the age at which rats are assessed may be an impo rtant factor, possibly reflecting a different course in the relatively protracted maturation of the hippocampus in male and female rats. The results of this investigation are also discussed with reference to st udies of sex differences for spatial abilities in humans.