Maternal protein malnutrition induces autism-like symptoms in rat offspring.

OBJECTIVE: We tested the correlation between maternal protein malnutrition and autistic-like symptoms using behavioral tests in rodents that measure main behavioral characteristics observed in humans with autism spectrum disorder (ASD).

METHODS: Pregnant female rats were fed a normal diet or a hypoproteic diet during gestation and lactation periods. The litters were weighed every 3 days during lactation, and the offspring were tested in behavioral tasks during infancy (postnatal day (PND) 5: quantification of ultrasonic vocalizations; PND 13: homing behavior test) and adolescence (PND 30-32: open field, hole-board, play social behavior, and object recognition tests) in order to capture the prevalence of some of the core and associated symptoms of ASD.

RESULTS: Litters of the hypoproteic diet group had a lesser weight gain during lactation. In addition, pups of dams fed with a hypoproteic diet vocalized less compared to those fed with a normal diet, and they showed impaired social discrimination abilities in the homing behavior test. In adolescence, both male and female offspring of the hypoproteic diet group showed no impairment in locomotor activity; however, they exhibited stereotypic behavior in the hole-board test and a decrease in social play behaviors. Male offspring showed increased interest in exploring a familiar object rather than a novel object.

CONCLUSION: Our results show that maternal protein malnutrition in rats causes offspring behaviors that resemble core and associated ASD symptoms.