Effects Of Environmental Magnetic Field On Chick Embryonic Development And Chick Cognition

Objective:The objective of this research was to study the effect of environmental magnetic field exposure on chick embryonic development and offspring cognition and the role of NMDA receptor in the learning and memory impairment.So as to provide a theoretical basis in protection againtist magnetic field.Methods:The chick embryo were exposed to microwave, extremely low-frequency electromagnetic field, and static magnetic field radiation source respectively( 1.5h/ day.) embryo day 1 (E1) to embryo day 20 (E20) . At the sametime, RT-PC was used to detect the expression of of NR1,NR2 subunits of NMDA receptor in the telencephalon of E10 and E15. Twenty-four hours after chicken hatched, a one-trial passive avoidance task (PAT) was used to test the effects of MF(magnetic field) exposed on learning and menory in offspring.Results: Prenatal MF exposure (microwave,extremely low-frequency electromagnetic field and static magnetic field) significantly increased the mean hatch weight, but not effected on hatching ratio. After the microwave radiation, the hatching time in one group increased and the avoidance rate in microwave-group is significantly lower at 120 min but not at 5min, compared with the control group. Extremely low-frequency and static magnetic field-group showed a significantly lower avoidance rate at 5 min and 120 min, compared with the sham-exposed group.The mRNA expression of NR1 subunit increased on E10 after microwave and extremely low-frequency radiation and down regulated after static magnetic field radiation.On E15, the expression of NR1 subunit decreased among three groups. The mRNA expression of NR2 subunit increased after static magnetic field and extremely low-frequency radiation and down regulated afte microwave radiation on E10. On E15, the expression of NR1 subunit increased among three groups.Conclusion: After prenatal MF exposure during incubation, NMDA receptor participates in the injury induced by MF radiation. The abonormal expression of of NR1, NR2 subunits of NMDA receptor may be the important mechanism of recognition disfunction caused by MF radiation.