RESUMEN
In Western society, impaired uteroplacental blood flow is the major cause of human intrauterine growth restriction. Infants born small and who experience late childhood accelerated growth have an increased risk of developing adult diseases. Recent studies also suggest a link between birth weight and altered adult behavior, particularly relating to motor function, learning and memory, depression and schizophrenia. The aim of this study was to determine the relative influence of prenatal and postnatal growth restriction on adult behavioral outcomes in male and female rats. Uteroplacental insufficiency was induced in Wistar Kyoto rats by bilateral uterine vessel ligation on day 18 of gestation producing growth-restricted offspring (Restricted group). The Control group had sham surgery. Another group underwent sham surgery, with a reduction in litter size to five at birth equivalent to the Restricted litter size (Reduced Litter group). At 6 months of age, a series of behavioral tests were conducted in male and female offspring. Growth restriction did not impair motor function. In fact, Restricted and Reduced Litter males showed enhanced motor performance compared with Controls (P < 0.05). Spatial memory was greater in Restricted females only (P < 0.05). The Porsolts test was unremarkable, however, males exhibited more depressive-like behavior than females (P < 0.05). A reduction in sensorimotor gating function was identified in Reduced Litter males and females (P < 0.05). We have demonstrated that growth restriction and/or a poor lactational environment can affect adult rat behavior, particularly balance and coordination, memory and learning, and sensorimotor gating function, in a sex-specific manner.