There is a need for improved understanding of interactions between electromagnetic fields and biological tissues. In this thesis, the effects of exposure to 50 Hz magnetic fields, associated with power generation and use, and 1800 MHz fields associated with mobile phones were investigated with particular focus on the plastic processes that are involved in cognitive function. After repeated, daily exposure of young adult C57Bl/6J mice to an 1800 MHz field at 3 W/kg, very subtle changes in expression of genes involved in synaptic plasticity were found (p < 0.05). Spatial memory as measured in the water maze was not significantly affected by exposure. Exposure at 0.3 W/kg did not significantly affect any of the endpoints (p > 0.05). Indications of a greater sensitivity to exposure at 3 W/kg were seen in a senescence accelerated prone mouse model (SAMP8) compared to a resistant strain (SAMR1). However, only subtle effects of exposure were seen. Exposure of young C57Bl/6J mice to a 50 Hz field at 100 or 300 μT induced small but significant changes in expression in synaptic plasticity related genes (p < 0.05). Furthermore, repeated exposure significantly increased microglial density in the dorsal hippocampus (p < 0.05) and slightly decreased proliferation in the dorsal hippocampus (100 μT, p < 0.05). Spatial memory was not significantly affected by exposure. Acute exposure to a 50 Hz magnetic field for 30 minutes at 300 or 580 μT did not affect the adrenal response to a nocturnal white or blue light shock, while exposure at 580 μT in the absence of light significantly decreased per1 expression in the adrenal glands (p < 0.05), but not in the liver or dorsal hippocampus. Exposure at 580 μT for 24 hours had only minor transient effects on the rhythmic expression of the core clock genes. In summary, exposure to 50 Hz or 1800 MHz fields caused subtle and transient changes to some molecular mechanisms and cells involved in cognitive function and circadian rhythm control.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:740959 |
| Date | January 2017 |
| Creators | Lundberg, Louise |
| Contributors | Anthony, Daniel ; Broom, Kerry A. ; Sienkiewicz, Zenon J. |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://ora.ox.ac.uk/objects/uuid:ec41f92c-f240-4821-8120-0d33a38d3eb7 |
Page generated in 0.1012 seconds