Effect of lead exposure during pregnant and lactation period on learning and memory ability of neonatal mice and the expression of IL-1β in hippocampus

Objective:To explore the effect of maternal lead exposure on the expression of IL-1β in hippocampus of neonatal mice.Methods:The female mice drank water with lead(0.3 g/L,1.0 g/L,3.0 g/L,respectively;the mice in control group drank distilled water) from the first day during pregnancy until the 21st day after birth of their offsprings.The neonatal mice were selected randomly from the four groups,the contents of lead in blood and hippocampus of neonatal mice were detected on the seventh,fourteenth and 21st day after birth.On the 21st day after birth,Y-type maze was used to detect the learning and memory ability of neonatal mice,the expression levels of IL-1β in hippocampus in the four groups were detected by immunohistochemical method.Results:After exposure to lead of different doses during pregnant and lactation period,the expression levels of IL-1β in blood and hippocampus of neonatal mice on the seventh,fourteenth and 21st day after birth were significantly higher than those in control group(P0.05).The results of Y-type maze showed that the abilities of obtaining memory(T1),retaining memory(T2) and the memory retaining rate(T3) in lead exposure group of low dose,lead exposure group of moderate dose and lead exposure group of high dose on the 21st day were significantly lower than those in control group on the 21st day(P0.05).The results of immunohistochemical method showed that the areal densities of positive immunohistochemical reactant of IL-1β in CA1 region of hippocampus of neonatal mice in the three lead exposure groups were significantly higher than that in control group,while the average gray values of positive immunohistochemical reactant of IL-1β in CA1 region of hippocampus of neonatal mice in the three lead exposure groups were significantly lower than that in control group(P0.05).Conclusion:Maternal lead exposure induces lead accumulation in neonatal mice,enhances the expression of IL-1β in hippocampus of neonatal mice,which interferes the function of neurons in hippocampus and further affects the learning and memory ability of neonatal mice.