Abnormality of synaptic vesicular associated proteins in cerebral cortex and hippocampus after microwave exposure

Synapse. 2009 Nov;63(11):1010-6. doi: 10.1002/syn.20684.

Abstract

Studies were performed to determine the effects of microwave on synaptic vesicles and the expression of synaptic vesicular associated proteins including synapsin I, VAMP-2, syntaxin, and synaptophysin. 25 Wistar rats were exposed to microwave which the average power density was 30 mW/cm(2), and whole body average specific absorption rate was 14.1 W/kg for 5 min. Synaptosome preparations in the cerebral cortex and hippocampus were obtained by isotonic Percoll/sucrose discontinuous gradients at 6 h, 1, 3, and 7 days after radiation. The expression of synaptic vesicular associated proteins was measured using Western blots and image analysis. The interaction between VAMP-2 and syntaxin was examined by coimmunoprecipitation analysis. Synapsin I in the cerebral cortex were decreased at 3 days (P < 0.01) after radiation and in the hippocampus increased at 1 day (P < 0.01), decreased at 3 days (P < 0.01), increased again at 7 days (P < 0.01) after exposure, compared with the sham-treated controls. Synaptophysin were increased in 1-7 days (P < 0.01) after exposure in the cerebral cortex and hippocampus. VAMP-2 were decreased at 1 and 3 days (P < 0.01) and syntaxin were decreased in 6 h to 3 days (P < 0.01) after radiation in the cerebral cortex and hippocampus. The interactions between VAMP-2 and syntaxin were decreased at 3-7 days (P < 0.01) after radiation in the cerebral cortex and hippocampus, compared with the sham-treated controls. These results suggest that 30 mW/cm(2) (SAR 14.1 W/kg) microwave radiation can result in the perturbation of the synaptic vesicles associated proteins: synapsin I, synaptophysin, VAMP-2, and syntaxin. The perturbation could induce the deposit of synaptic vesicle, which might be relative to the dysfunction of the synaptic transmission, even the cognition deficit.

MeSH terms

  • Animals
  • Blotting, Western
  • Cerebral Cortex / metabolism
  • Cerebral Cortex / radiation effects*
  • Hippocampus / metabolism
  • Hippocampus / radiation effects*
  • Immunoprecipitation
  • Male
  • Microwaves
  • Qa-SNARE Proteins / metabolism
  • Qa-SNARE Proteins / radiation effects
  • Rats
  • Rats, Wistar
  • Synapsins / metabolism
  • Synapsins / radiation effects
  • Synaptic Vesicles / metabolism
  • Synaptic Vesicles / radiation effects*
  • Synaptophysin / metabolism
  • Synaptophysin / radiation effects
  • Vesicle-Associated Membrane Protein 2 / metabolism
  • Vesicle-Associated Membrane Protein 2 / radiation effects

Substances

  • Qa-SNARE Proteins
  • Synapsins
  • Synaptophysin
  • Vesicle-Associated Membrane Protein 2