Effect of 835 MHz Radiofrequency Radiation Exposure on Calcium Binding Proteins in the Hippocampus of the Mouse Brain

Brain Res. 2010 Feb 8;1313:232-41. doi: 10.1016/j.brainres.2009.11.079. Epub 2009 Dec 5.

Abstract

Worldwide expansion of mobile phones and electromagnetic field (EMF) exposure has raised question of their possible biological effects on the brain and nervous system. Radiofrequency (RF) radiation might alter intracellular signaling pathways through changes in calcium (Ca(2+)) permeability across cell membranes. Changes in the expression of calcium binding proteins (CaBP) like calbindin D28-k (CB) and calretinin (CR) could indicate impaired Ca(2+)homeostasis due to EMF exposure. CB and CR expression were measured with immunohistochemistry in the hippocampus of mice after EMF exposure at 835 MHz for different exposure times and absorption rates, 1 h/day for 5 days at a specific absorption rate (SAR)=1.6 W/kg, 1 h/day for 5 days at SAR=4.0 W/kg, 5 h/day for 1 day at SAR=1.6 W/kg, 5 h/day for 1 day at SAR=4.0 W/kg, daily exposure for 1 month at SAR=1.6 W/kg. Body weights did not change significantly. CB immunoreactivity (IR) displayed moderate staining of cells in the cornu ammonis (CA) areas and prominently stained granule cells. CR IR revealed prominently stained pyramidal cells with dendrites running perpendicularly in the CA area. Exposure for 1 month produced almost complete loss of pyramidal cells in the CA1 area. CaBP differences could cause changes in cellular Ca(2+)levels, which could have deleterious effect on normal hippocampal functions concerned with neuronal connectivity and integration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorption
  • Animals
  • Body Weight / radiation effects
  • CA1 Region, Hippocampal / physiology
  • CA1 Region, Hippocampal / radiation effects
  • Calbindin 2
  • Calbindins
  • Cell Count
  • Electromagnetic Fields / adverse effects
  • Hippocampus / physiology
  • Hippocampus / radiation effects*
  • Immunohistochemistry
  • Male
  • Mice
  • Mice, Inbred ICR
  • Neurons / physiology
  • Neurons / radiation effects*
  • Photomicrography
  • Pyramidal Cells / physiology
  • Pyramidal Cells / radiation effects
  • Radiation Dosage
  • Radio Waves / adverse effects*
  • S100 Calcium Binding Protein G / metabolism*
  • Time Factors

Substances

  • Calb2 protein, mouse
  • Calbindin 2
  • Calbindins
  • S100 Calcium Binding Protein G