不同频率及功率密度毫米波辐射对子代学习记忆功能及脑胆碱能-M受体的影响

Effects of Millimeter Wave Irradiation with Different Frequencyat Different Power Density on the Learning Capacity and Memoryof the Adult Offspring,and on the M-R of Posterities

为阐明毫米波对胚胎产生损伤效应的阈值及导致成年子鼠学习记忆功能降低的机理，验证毫米波有无频率特异性。用３７．４～６０ＧＨｚ，功率密度１ｍＷ／ｃｍ２～８ｍＷ／ｃｍ２毫米波，在小鼠怀孕６ｄ～１５ｄ时进行２ｈ／ｄ辐射，用电迷宫对成年子鼠进行学习记忆功能测试，用受体放射配基结合分析（ＲＢＡ）对子鼠脑胆碱能－Ｍ受体（Ｍ－Ｒ）进行测定。结果显示：３７．４，４２．２ＧＨｚ毫米波，≥５ｍＷ／ｃｍ２辐射可导致成年子鼠学习记忆功能降低，成年子鼠海马区Ｂｍａｘ明显升高；５３，６０ＧＨｚ毫米波，≥３ｍＷ／ｃｍ２辐射可导致成年子鼠学习记忆功能降低，成年子鼠海马区Ｂｍａｘ明显升高。毫米波辐射未使孕鼠肛温及辐射区皮肤温度明显升高。认为：３７．４，４２．２ＧＨｚ和５３，６０ＧＨｚ毫米波导致胚胎损伤阈值分别在３ｍＷ／ｃｍ２～５ｍＷ／ｃｍ２和１ｍＷ／ｃｍ２～３ｍＷ／ｃｍ２，其导致子鼠学习记忆功能降低与使成年子鼠海马区胆碱能神经活性下降相关，此效应由毫米波非热效应所致，未见毫米波的频率特异性。

To determine the threshold of fetuses injury induced by millimeter wave irradiation and to clarify the mechanism of lowering learning capacity and memory of the adult offspring, and to verify whether millimeter wave has effect of frequencyspecific.Twomonth old BALB/c mice were separately irradiated by millimeter wave with frequencies of 374￣60 GHz at power densities of 1￣8 mW/cm2 for 2 h daily from the 6th to 15th day of gestation.The test of learning capacity and memory of adult offspring were employed on Ytype electric maze.The quantity of MR and its affinity to ligand in the brain of the fetuses at term, adult offspring were measured by using RBA.The results revealed that: with frequencies of 374 and 422 GHz, millimeter wave irradiation at power densities of ≥5 mW/cm2 lowered learning capacity and memory of adult offspring; It significantly increased the quantity of MR in hippocampus of adult offspring.With frequencies of 53 and 60 GHz, millimeter wave irradiation at power densities of ≥3 mW/cm2 lowered learning capacity and memory of the adult offspring; It significantly increased the quantity of MR in hippocampus of adult offspring.Millimeter wave irradiation didn′t significantly increased the skin temperature of the pregnant mice.It is suggested that the thresholds of fetuses injury induced by millimeter wave irradiation to pregnant mice with frequencies of 374 GHz, 422 GHz and 53 GHz, 60 GHz are between 3 mW/cm2￣5 mW/cm2, 1mW/cm2￣3 mW/cm2 separately.The mechanism that millimeter wave irradiation lowered learning capacity and memory of the adult offspring is closely related to a reduction of cholinergic nervous function in the hippocampus.There is the athermal effect of millimeter wave.There isn′t the effect of frequencyspecific.