title: Alterations of cognitive function and 5-HT system in rats after long term microwave exposure.
abstract: The increased use of microwaves raises concerns about its impact on health including cognitive function in which neurotransmitter system plays an important role. In this study, we focused on the serotonin system and evaluated the long term effects of chronic microwave radiation on cognition and correlated items. Wistar rats were exposed or sham exposed to 2.856GHz microwaves with the average power density of 5, 10, 20 or 30mW/cm(2) respectively for 6min three times a week up to 6weeks. At different time points after the last exposure, spatial learning and memory function, morphology structure of the hippocampus, electroencephalogram (EEG) and neurotransmitter content (amino acid and monoamine) of rats were tested. Above results raised our interest in serotonin system. Tryptophan hydroxylase 1 (TPH1) and monoamine oxidase (MAO), two important rate-limiting enzymes in serotonin synthesis and metabolic process respectively, were detected. Expressions of serotonin receptors including 5-HT1A, 2A, 2C receptors were measured. We demonstrated that chronic exposure to microwave (2.856GHz, with the average power density of 5, 10, 20 and 30mW/cm(2)) could induce dose-dependent deficit of spatial learning and memory in rats accompanied with inhibition of brain electrical activity, the degeneration of hippocampus neurons, and the disturbance of neurotransmitters, among which the increase of 5-HT occurred as the main long-term change that the decrease of its metabolism partly contributed to. Besides, the variations of 5-HT1AR and 5-HT2CR expressions were also indicated. The results suggested that in the long-term way, chronic microwave exposure could induce cognitive deficit and 5-HT system may be involved in it.
authors.affiliation: Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China; 205 Hospital, JinZhou, Liaoning, China.
authors.forename: Hai-Juan
authors.initials: HJ
authors.lastname: Li
authors.affiliation: Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China.
authors.forename: Rui-Yun
authors.initials: RY
authors.lastname: Peng
authors.affiliation: Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China.
authors.forename: Chang-Zhen
authors.initials: CZ
authors.lastname: Wang
authors.affiliation: Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China.
authors.forename: Si-Mo
authors.initials: SM
authors.lastname: Qiao
authors.affiliation: Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China.
authors.forename: Zou
authors.initials: Z
authors.lastname: Yong
authors.affiliation: Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China.
authors.forename: Ya-Bing
authors.initials: YB
authors.lastname: Gao
authors.affiliation: Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China.
authors.forename: Xin-Ping
authors.initials: XP
authors.lastname: Xu
authors.affiliation: Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China.
authors.forename: Shao-Xia
authors.initials: SX
authors.lastname: Wang
authors.affiliation: Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Dong
authors.affiliation: Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China.
authors.forename: Hong-Yan
authors.initials: HY
authors.lastname: Zuo
authors.affiliation: Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Radiation Protection and Health, Beijing Institute of Radiation Medicine, Beijing, China.
authors.forename: Hong-Mei
authors.initials: HM
authors.lastname: Zhou
authors.affiliation: Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China. Electronic address: fangchang_14@163.com.
authors.forename: Li-Feng
authors.initials: LF
authors.lastname: Wang
authors.affiliation: Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China. Electronic address: xjhu2003@vip.sina.com.
authors.forename: Xiang-Jun
authors.initials: XJ
authors.lastname: Hu
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000473:pathology / Q000528:radiation effects*; D058256:Brain Waves / Q000528:radiation effects; D003072:Cognition Disorders / Q000209:etiology*; D004307:Dose-Response Relationship, Radiation; D004569:Electroencephalography; D008297:Male; D018782:Maze Learning / Q000528:radiation effects; D008872:Microwaves / Q000009:adverse effects*; D009410:Nerve Degeneration / Q000209:etiology; D018377:Neurotransmitter Agents / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000528:radiation effects; D011985:Receptors, Serotonin / Q000235:genetics / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism*; D013550:Swimming / Q000523:psychology; D013995:Time; D013997:Time Factors; D014365:Tryptophan Hydroxylase / Q000378:metabolism
chemical_list: D018377:Neurotransmitter Agents; D011985:Receptors, Serotonin; D012701:Serotonin; D014365:Tryptophan Hydroxylase
keywords: 5-HT receptor; Electromagnetic radiation; Hippocampus; Learning and memory; Microwave; Neurotransmitters; Serotonin