Protein malnutrition during pregnancy alters maternal behavior and anxiety-like behavior in offspring

The aim of this study was to evaluate the effects of protein malnutrition during pregnancy on maternal behavior, on the early behavior in pups by ultrasonic vocalizations (USVs) emission, and on the behavior of offspring in adulthood in an elevated T-maze.

Pregnant female rats were fed a normal protein-powdered diet (22% casein; control) or a low-protein (hypoproteic) diet (6% casein; protein restriction) during the first 2 weeks of pregnancy. On the fifth postpartum day (PND5), the number of USV was rated. On PND7, maternal behavior was assessed. Male offspring in adulthood were evaluated for behavioral performance in an elevated T-maze.

Our results demonstrated that a hypoproteic diet during early pregnancy increased the maternal behavior, increased the number of USV by pups, and reduced the inhibitory avoidance responses in an elevated T-maze during adulthood. In addition, there was a reduction in weight gain of rats during pregnancy and of offspring during lactation.

In conclusion, the data found in our study suggest that the increase in USV emitted by pups due to hypoproteic diet during pregnancy accentuated maternal behavior. In addition, an increase in maternal care promoted the reduction in anxiety-like behavior in adult male offspring.