Effects of Prenatal Exposure to a 50-Hz Magnetic Field on One-Trial Passive Avoidance Learning in 1-Day-Old Chicks

We investigated memory impairment in newly hatched chicks following in ovo exposure to a 50-Hz magnetic field (MF) of 2 mT (60 min/day) on embryonic days 12-18. Isolated and paired chicks were used to test the effect of stress during training, and memory retention was tested at 10, 30, and 120 min, following exposure to a bitter-tasting bead (100% methylanthranilate). Results showed that memory was intact at 10 min in both isolated and paired chicks with or without MF exposure. However, while isolated chicks had good memory retention levels at 30 and 120 min, those exposed to MF did not. The results suggest a potential disruption of memory formation following in ovo exposure to MF, with this effect only evident in the more stressed, isolated chicks. Bioelectromagnetics 31:150-155, 2010. (C) 2009 Wiley-Liss. Inc.

We are indebted to the faculty and staff of Beijing Genomics Institute at Shenzhen, whose names were not included in the author list, but who contributed to this team work. This project is funded by the Shenzhen Municipal Government and the Yantian District local government of Shenzhen. This project is supported by the National Natural Science Foundation of China (30725008), Ole Romer grant from the Danish Natural Science Research Council, the Solexa project (272-07-0196), and Danish Strategic Research Council (2106-07-0021). We thank C. Wang, X. Huang and L. Luo for their assistance in collecting the blood sample. We thank D. D. Pollock for repeat content estimation. We thank M. Shi, Y. Wang and M. Ting Wong for analysis of the reproduction related genes. We also thank L. Goodman for editing the manuscript.