Maternal Zinc Supplementation Improves Spatial Memory in Rat Pups

Abstract

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 ZnSO 4 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 ZnSO 4 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. ZnSO 4 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.

High Dose Zinc Supplementation Induces Hippocampal Zinc Deficiency and Memory Impairment with Inhibition of BDNF Signaling

“…Flinn JM et al reported in a series of publications that enhanced zinc (10 ppm) consumption causes memory deficits in rats [19], [32] and potentiates memory impairment in transgenic disease mouse models [33], [34], while others observed improved performance of the animals in spatial memory tasks [35], [36]. In our experiments, we also observed improved performance of mice in contextual discrimination task.…”

Zinc homeostasis and neurodegenerative disorders

“…First, the effect of zinc supplementation on learning and memory impairments is dose dependent. Generally, zinc supplementation in a low dosage seems to improve the performance of animals in spatial memory tasks (Piechal et al, 2012) or the contextual discrimination task (Yang et al, 2013). However, memory deficits in rats after low dose of zinc supplementation were also observed (Flinn et al, 2005; Railey et al, 2010).…”

Zinc in the central nervous system: From molecules to behavior

“…It should be noted that these deficits persisted into adulthood long after zinc nutriture had been reestablished [12]. More recently, rat pups born of dams receiving pre- and postnatal zinc supplementation showed significant improvements in memory as well as an increase in serum zinc levels compared to controls, indicating that zinc supplementation positively impacts early cognitive development [13]. Furthermore, there is some evidence to suggest that rats fed a zinc-supplemented diet after birth may be more resistant to subsequent diet-induced zinc deficiency [14].…”