Backgrounds and aims Intrauterine growth restriction (IUGR) and rapid postnatal weight gain increase susceptibility to metabolic syndrome during adult life. Longitudinal studies have also revealed high incidence of learning difficulties in children with IUGR.

The aim of the present study was to investigate the effect of nutrition on learning memory in an IUGR animal model.

Methods We use a mouse model of IUGR induced by caloric maternal undernutrition during late gestation. During the suckling period, dams were either fed ad libitum or food restricted. Pups were dived into: control-control (CC), undernutrition-control (UC), control-undernutriton (CU) and undernutrition-undernutrition (UU), indicating the prenatal-postnatal experimental conditions.

At 4 weeks of age, memory was assessed via water maze test. Finally, rats were anaesthetised and sacrified. To assess possible alterations of the hippocampal synaptic network, 3 specific synaptic proteins (PSD95, SNAP25, synaptophysin) were tested by Western Blot.

Results CC, UC, CU exhibited shorter escape latencies (EL) along the days. UU hardily changed its EL, indicating a poor spatial memory performance. Learning differences between CC and UU were statistical significant (p < 0,01). CC animals had the higher protein synaptic levels in the hippocampus compared to all other groups (p < 0,05).

Conclusions Nutrition plays an important role in learning. A poor pre and postnatal nutrition is associated with learning and memory alterations. Catch-up growth group showed an improvement in learning compared to UU. A decreased level of synaptic proteins in animals with a deficient nutrition (pre, postnatal or both), suggests that malnutrition results in less functional or efficient synapses.