Microwave radiation leading to shrinkage of dendritic spines in hippocampal neurons mediated by SNK-SPAR pathway

Brain Res. 2018 Jan 15:1679:134-143. doi: 10.1016/j.brainres.2017.11.020. Epub 2017 Nov 24.

Abstract

The popularization of microwave raised concerns about its influence on health including cognitive function which is associated greatly with dendritic spines plasticity. SNK-SPAR is a molecular pathway for neuronal homeostatic plasticity during chronically elevated activity. In this study, Wistar rats were exposed to microwaves (30 mW/cm2 for 6 min, 3 times/week for 6 weeks). Spatial learning and memory function, distribution of dendritic spines, ultrastructure of the neurons and their dendritic spines in hippocampus as well as the related critical molecules of SNK-SPAR pathway were examined at different time points after microwave exposure. There was deficiency in spatial learning and memory in rats, loss of spines in granule cells and shrinkage of mature spines in pyramidal cells, accompanied with alteration of ultrastructure of hippocampus neurons. After exposure to 30 mW/cm2 microwave radiation, the up-regulated SNK induced decrease of SPAR and PSD-95, which was thought to cause the changes mentioned above. In conclusion, the microwave radiation led to shrinkage and even loss of dendritic spines in hippocampus by SNK-SPAR pathway, resulting in the cognitive impairments.

Keywords: Dendritic spines; Learning and memory; Microwave radiation; SNK-SPAR pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dendritic Spines / radiation effects*
  • Dendritic Spines / ultrastructure
  • Disks Large Homolog 4 Protein / genetics
  • Disks Large Homolog 4 Protein / metabolism
  • GTPase-Activating Proteins / genetics
  • GTPase-Activating Proteins / metabolism*
  • GTPase-Activating Proteins / ultrastructure
  • Hippocampus / cytology*
  • Hippocampus / radiation effects
  • Male
  • Maze Learning / radiation effects
  • Microscopy, Electron, Transmission
  • Microwaves / adverse effects*
  • Neurons / radiation effects
  • Neurons / ultrastructure*
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Wistar
  • Signal Transduction / radiation effects*
  • Silver Staining
  • Synapses / metabolism
  • Synapses / radiation effects
  • Synapses / ultrastructure
  • Time Factors
  • Up-Regulation / radiation effects

Substances

  • Disks Large Homolog 4 Protein
  • GTPase-Activating Proteins
  • RNA, Messenger
  • Sipa1l1 protein, rat
  • Protein Serine-Threonine Kinases