Spatial learning ability of rats undernourished during early postnatal life.

Experiments to determine whether undernutrition during early life results in deficits in spatial learning behavior has produced conflicting results. It was hypothesized that this may be due to the differing degrees of undernutrition used in the various studies, and/or to the timing of the testing procedures with respect to the period of food deprivation. These possibilities were tested by undernourishing rats between birth and 30 days of age to two different levels (i.e., level-1 and level-2). The degree of undernutrition was greater at level-2 than level-1. Behavioral testing of these rats and well-fed controls was carried out in the Morris water maze when they were between either 35 and 65 or 170 and 200 days of age. Statistical analyses of the escape latency data from these experiments revealed that rats tested almost immediately after the period of undernutrition have alterations in their spatial learning behavior compared with controls. However, even a short period of nutritional rehabilitation removed any differences between control and previously undernourished groups, irrespective of the level of undernutrition.