Maternal Zinc Supplementation Improves Spatial Memory in Rat Pups

A large body of evidence supports an opinion that adequate dietary zinc is essential for prenatal and postnatal brain development. Behavioural effects of maternal supplementation with ZnSO4 were analysed in rat pups with the Morris water task performance, a hole board and a T-maze. Wistar females during pregnancy and lactation received a drinking water solution of ZnSO4 at doses of 16 mg/kg (group Zn16) or 32 mg/kg (group Zn32). Behavioural tests were conducted on the 4-week-old male rat pups. Zinc concentration in the serum, hippocampus and prefrontal cortex of offsprings was determined by means of atomic absorption techniques. The Newman-Keuls multiple comparison test revealed an increase of climbing in the Zn16 group in comparison to the control group (Con) and the Zn32 group during the hole board test. ANOVA for repeated measures showed a significant memory improvement in both supplemented groups compared to the control in the probe trial on day 5 of the water maze test. ZnSO4 treatment significantly elevated zinc levels in the rat serum. Follow-up data on brain content of zinc in the hippocampus revealed significant differences between the groups and in supplemented groups correlated with crossings above the original platform position. These findings suggest that pre- and postnatal zinc supplementation may improve cognitive development in rats.