Pre- and/or postnatal protein restriction developmentally programs affect and risk assessment behaviors in adult male rats

Abstract

Developmental programming resulting from a suboptimal intrauterine environment can predispose offspring to a wide-range of lifelong health complications. Little is known about the effects maternal protein restriction during pregnancy and/or lactation has on offspring neurodevelopment. We hypothesized that maternal isocaloric low protein diet during pregnancy and/or lactation would negatively influence male offspring affect and risk assessment behaviors as measured by elevated plus maze and open field tests. Control mothers received 20% casein (C) and restricted mothers (R) 10% casein to provide four groups: CC, RR, CR, and RC (first letter pregnancy diet and second letter lactation diet) to evaluate effects of maternal diet on offspring risk assessment, anxiety and exploratory behaviors. Elevated plus maze results showed an effect of pre- and/or postnatal diet manipulation in open arm time (p<0.05) with increases seen in the RR (157±22.7s), CR (137±23.2s) and RC (146.8±10.8s) offspring relative to CC (52±8.6s) offspring. This behavior indicates decreased avoidance (less anxiety) and increased exploration by experimental groups. However, in the open field test the RR (17±4.2 entries) offspring entered the center zone less than the CC (35±6.6 entries) offspring thus exhibiting increased anxiety with no other groups showing effects. Elevated levels of corticosterone were measured before, during and after immobilization in the RR compared to CC offspring. These findings show protein restriction during critical periods of development negatively program offspring behavior. The underlying anatomical structures affected remain to be elucidated.