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Abstract: Maternal protein deficiencies can developmentally program offspring to lifelong dysfunction of many physiological systems. We hypothesized that maternal isocaloric low protein diet during fetal and early postnatal development would negatively affect female offspring anxiety, exploration, associative learning and motivation as measured by the elevated plus maze (EPM), open field test (OFT), operant conditioning and the progressive ratio task, respectively. Control mothers (C) received a 20% casein diet and restricted mothers (R) a 10% casein diet to provide four groups: CC, RR, CR, and RC (first letter pregnancy diet and second lactation diet) to enable evaluation of offspring effects influenced by maternal diet during pregnancy and lactation. Maternal protein restriction decreased open arm time and distance in RR and RC offspring, increased anxiety behavior, in the EPM. In the OFT, the RR and RC offspring displayed decreased exploration (increased stress) as indexed by decreased distance in the center zone. These behaviors in the EPM and OFT was associated with increased corticosterone levels during an immobilization test in the RR offspring with intermediary effects in the RC offspring. Learning impairment was observed in the RR, CR and RC offspring during fixed ratio 5 schedule of reinforcement. Motivational effects were measured in RR offspring responding less, decreased motivation, and CR offspring making more responses, increased motivation, than CC offspring. These findings reveal the negative effects of developmental protein restriction on female offspring behavior. The underlying basis for these negative outcomes remains to be elucidated. [Copyright &y& Elsevier]

Abstract: Suboptimal developmental environments program offspring to lifelong health complications including affective and cognitive disorders. Little is known about the effects of suboptimal intra-uterine environments on associative learning and motivational behavior. We hypothesized that maternal isocaloric low protein diet during pregnancy and lactation would impair offspring associative learning and motivation as measured by operant conditioning and the progressive ratio task, respectively. Control mothers were fed 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 male offspring behavior. Impaired learning was observed during fixed ratio−1 operant conditioning in RC offspring that required more sessions to learn vs. the CC offspring (9.4±0.8 and 3.8±0.3 sessions, respectively, p <0.05). Performance in fixed ratio−5 conditioning showed the RR (5.4±1.1), CR (4.0±0.8), and RC (5.0±0.8) offspring required more sessions to reach performance criterion than CC offspring (2.5±0.5, p <0.05). Furthermore, motivational effects during the progressive ratio test revealed less responding in the RR (48.1±17), CR (74.7±8.4), and RC (65.9±11.2) for positive reinforcement vs. the CC offspring (131.5±7.5, p <0.05). These findings demonstrate negative developmental programming effects due to perinatal isocaloric low protein diet on learning and motivation behavior with the nutritional challenge in the prenatal period showing more vulnerability in offspring behavior. [Copyright &y& Elsevier]