[Relationship between millimeter wave irradiation in pregnant mice and c-Fos protein expression in hippocampus and learning and memory functions in their offsprings].
OBJECTIVE
To determine the threshold of millimeter wave irradiation for fetal injury in mice and the mechanism of decrease of learning and memory function in their offsprings and to verify whether the millimeter wave has the non-thermal effect.


METHODS
Pregnant mice were irradiated by millimeter wave with frequencies of 37.4, 42.2, 53.0 and 60.0 GHz at power densities of 1, 3, 5, 8 mW/cm(2) for two hours daily from the 6th to 15th day of their gestation. Learning and memory functions of their offsprings were tested by a Y-type electric maze. c-Fos protein expression level in hippocampus of their offsprings was determined with immunohistochemistry 0, 30, 60, 90 and 120 minutes after the offsprings were trained respectively.


RESULTS
The minimal power density of millimeter wave for the decrease in learning and memory function and decrease of c-Fos protein expression level in hippocampus of their offsprings caused by 37.4, 42.2 GHz and 53.0, 60.0 GHz was 5 and 3 mW/cm(2). Severity of injury for learning and memory in offsprings caused by irradiation increased with the power density of millimeter wave. The millimeter wave did not cause increase of the body temperature of the pregnant mice.


CONCLUSIONS
The threshold of millimeter wave with 37.4, 42.2 GHz, and 53.0, 60.0 GHz causing fetal injury in mice is 5 and 3 mW/cm(2) respectively. The decrease in learning and memory functions in offspring mice is related with decrease of c-Fos protein expression level in hippocampus. Millimeter wave has the non-thermal effects.
Zhao
Zhi-gang
ZG
Department of Epidemiology, 210 th Hospital of PLA, Dalian 116021, China.
Zhang
Jin-feng
JF
Yan
Ping
P
Ma
Yan-mei
YM
D000818:Animals; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006624:Hippocampus / Q000378:metabolism / Q000528:radiation effects*; D007150:Immunohistochemistry; D007858:Learning / Q000528:radiation effects*; D008568:Memory / Q000528:radiation effects*; D051379:Mice; D008807:Mice, Inbred BALB C; D008872:Microwaves / Q000009:adverse effects*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*
D016760:Proto-Oncogene Proteins c-fos