An analysis of spatial navigation in prenatally protein malnourished rats.

Developing rats were either malnourished or adequately nourished during the prenatal period by feeding their dams diets of low (6% casein) or adequate (25% casein) protein content 5 weeks prior to mating and throughout pregnancy. All pups received adequate nutrition from the day of birth onwards. Male offspring were tested in one of two spatial navigation tests in the Morris water tank. In proximal-cue tests (postnatal days 16-20), the position of a platform, which provided a means to escape from swimming, was denoted by an obvious visual cue located directly on the platform. In distal-cue tests (postnatal days 20-27 and adult ages, days 70-71 and days 220-221), the escape platform was submerged below the surface of the water so that the rats were required to use extramaze visual cues to guide them to the platform. Neither proximal-cue nor distal-cue navigation was significantly impaired in the prenatally malnourished rats relative to controls, at any of the ages tested.