PRENATAL PROTEIN-MALNUTRITION AFFECTS AVOIDANCE BUT NOT ESCAPE BEHAVIOR IN THE ELEVATED T-MAZE TEST

An elevated T-maze was used to study the effects of prenatal protein d eficiency on inhibitory avoidance and escape behaviors. Female rats we re provided with a 25% (control) or a 6% (low protein) casein diets be fore and during pregnancy. After birth, eight pups in each litter (six males and two females) were fostered to a lactating well-nourished mo ther. After weaning (21 days of age) all animals received a lab chow d iet. Behavioral testing of these offspring began at 70 days of age. To assess inhibitory avoidance, prenatally malnourished and control rats were placed individually at the end of an enclosed arm in an elevated T-maze (one enclosed and two open arms) and the time taken to emerge from this arm was recorded. The same procedure was repeated in 2 subse quent trials given at 30-s intervals. Thirty seconds after the last of these trials, the rat was placed at the end of one open arm and the t ime taken to withdraw from this arm was measured, thus estimating esca pe latency. To assess retention, inhibitory avoidance and escape were measured again 72 h later. Prenatally malnourished males and females d id not significantly increase avoidance latency from trials 1-3, in co ntrast to male and female controls. Only control female rats significa ntly reduced their avoidance latency on the retention test. No signifi cant differences in escape latency were found between diet groups. The se results suggest that prenatal malnutrition results in a reduction o f anxiety, and that there are gender-specific responses to this test.