title: Relationship between cognition function and hippocampus structure after long-term microwave exposure.
abstract: OBJECTIVE
  To analyze the effects of long-term microwave exposure on hippocampal structure and function in the rat.
  
  
  METHODS
  Experiments were performed on 184 male Wistar rats (three exposure groups and a sham group). Microwaves were applied daily for 6 min over 1 month at average power densities of 2.5, 5, and 10 mW/cm2. Learning and memory abilities were assessed by Morris water maze. High performance liquid chromatography was used to detect neurotransmitter concentrations in the hippocampus. Hippocampal structures were observed by histopathological analysis.
  
  
  RESULTS
  Following long-term microwave exposure there was a significant decrease in learning and memory activity in the 7 d, 14 d, and 1 m in all three microwave exposure groups. Neurotransmitter concentrations of four amino acids (glutamate, aspartic acid, glycine, and gamma-aminobutyric acid) in hippocampus were increased in the 2.5 and 5 mW/cm2 groups and decreased in the 10 mW/cm2 group. There was evidence of neuronal degeneration and enlarged perivascular spaces in the hippocampus in the microwave exposure groups. Further, mitochondria became swollen and cristae were disordered. The rough endoplasmic reticulum exhibited sacculated distension and there was a decrease in the quantity of synaptic vesicles.
  
  
  CONCLUSIONS
  These data suggest that the hippocampus can be injured by long-term microwave exposure, which might result in impairment of cognitive function due to neurotransmitter disruption.
authors.affiliation: Beijing Institute of Radiation Medicine, Beijing 100850, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhao
authors.forename: Rui Yun
authors.initials: RY
authors.lastname: Peng
authors.forename: Shui Ming
authors.initials: SM
authors.lastname: Wang
authors.forename: Li Feng
authors.initials: LF
authors.lastname: Wang
authors.forename: Ya Bing
authors.initials: YB
authors.lastname: Gao
authors.forename: Ji
authors.initials: J
authors.lastname: Dong
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.forename: Zhen Tao
authors.initials: ZT
authors.lastname: Su
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003071:Cognition; D006624:Hippocampus / Q000473:pathology / Q000503:physiopathology* / Q000528:radiation effects; D007858:Learning; D008297:Male; D008568:Memory; D046529:Microscopy, Electron, Transmission; D008872:Microwaves; D051381:Rats; D017208:Rats, Wistar