Research reportSpatial learning, monoamines and oxidative stress in rats exposed to 900Â MHz electromagnetic field in combination with iron overload

- Rats exposed to 900 MHz electromagnetic field (EMF) combined or not with iron supplementation.
- Rats trained in spatial tasks, biogenic monoamines and oxidative stress measured.
- EMF: deficits in the exploration task only, monoamines altered and no global oxidative stress.
- EMF + iron overload: no greater behavioral and neurochemical deficits than EMF alone.
- EMF affects cognitive and neurochemical processes but no synergistic effects between EMF and iron.

The increasing use of mobile phone technology over the last decade raises concerns about the impact of high frequency electromagnetic fields (EMF) on health. More recently, a link between EMF, iron overload in the brain and neurodegenerative disorders including Parkinson's and Alzheimer's diseases has been suggested. Co-exposure to EMF and brain iron overload may have a greater impact on brain tissues and cognitive processes than each treatment by itself. To examine this hypothesis, Long-Evans rats submitted to 900 MHz exposure or combined 900 MHz EMF and iron overload treatments were tested in various spatial learning tasks (navigation task in the Morris water maze, working memory task in the radial-arm maze, and object exploration task involving spatial and non spatial processing). Biogenic monoamines and metabolites (dopamine, serotonin) and oxidative stress were measured. Rats exposed to EMF were impaired in the object exploration task but not in the navigation and working memory tasks. They also showed alterations of monoamine content in several brain areas but mainly in the hippocampus. Rats that received combined treatment did not show greater behavioral and neurochemical deficits than EMF-exposed rats. None of the two treatments produced global oxidative stress. These results show that there is an impact of EMF on the brain and cognitive processes but this impact is revealed only in a task exploiting spontaneous exploratory activity. In contrast, there are no synergistic effects between EMF and a high content of iron in the brain.