Influence of static electric field on cognition in mice
ABSTRACT
With the rapid development of high voltage direct current transmission, the possibility of health effects associated with static electric field (SEF) has caused wide public concern. To examine the effects of long-lasting, full-body exposure to SEF on cognition, Institute of Cancer Research mice were exposed to SEF for 35 d. The intensities of SEF in experimental group I (EG-I), experimental group II (EG-II) and control group (CG) were 2.30∼15.40 kV/m, 9.20∼21.85 kV/m and 0 kV/m, respectively. The performance in learning and memory of mice were tested by Morris water maze (MWM) on days 2∼6, 16∼20 and 30∼34 during the exposure period. The concentrations of hippocampal amino acid neurotransmitters were evaluated on days 7, 21 and 35. Results showed that the latency in the MWM test had no significant difference among the EG-I, EG-II and CG (P > 0.05) during the exposure period. The percentage of time spent in the target quadrant was significantly decreased in the EG-II on day 34 during the exposure period (P < 0.05), whereas the percentage of time spent in the opposite quadrant increased markedly (P < 0.01). The glutamate and gamma-aminobutyric acid concentrations showed no significant differences among the EG-I, EG-II and CG (P > 0.05) during the exposure period. These results indicated that long-lasting, full-body exposure to SEF with certain intensity would not cause significant influence on learning ability, but it might associate with memory impairment of receptors. Meanwhile, this effect of memory impairment was dose-dependent and not causally linked to the glutamate and gamma-aminobutyric acid levels in the hippocampus.
References
- 1. Jadidi M, Firoozabadi SM, Rashidy-Pour A, Sajadi AA, Sadeghi H, Taherian AA. Acute exposure to a 50 Hz magnetic field impairs consolidation of spatial memory in rats. Neurobiol Learn Mem 2007; 88:387-92; PMID:17768075; http://dx.doi.org/10.1016/j.nlm.2007.07.010 [] [[PubMed]
- 2. Zhao QR, Lu JM, Yao JJ, Zhang ZY, Ling C, Mei YA. Neuritin reverses deficits in murine novel object associative recognition memory caused by exposure to extremely low-frequency (50 Hz) electromagnetic fields. Sci Rep 2015; 5:11768; PMID:26138388; http://dx.doi.org/10.1038/srep11768 ] [
- 3. Morris R. Developments of a water-maze procedure for studying spatial-learning in the rat. J Neurosci Meth 1984; 11:47-60; http://dx.doi.org/10.1016/0165-0270(84)90007-4 [] [[PubMed]
- 4. Andersen JD, Pouzet B Spatial memory deficits induced by perinatal treatment of rats with PCP and reversal effect of D-serine. Neuropsychopharmacol 2004; 29:1080-90; http://dx.doi.org/10.1038/sj.npp.1300394 [] [[PubMed][Google Scholar]
- 5. Cui B, Wu M, She X. Effects of chronic noise exposure on spatial learning and memory of rats in relation to neurotransmitters and NMDAR2B alteration in the hippocampus. J Occup Health 2009; 51:152-8; PMID:19225220; http://dx.doi.org/10.1539/joh.L8084 [] [[PubMed]
- 6. Li C, Xie ML, Luo FL, He C, Wang JL, Tan G, Hu ZA. The extremely low-frequency magnetic field exposure differently affects the AMPAR and NMDAR subunit expressions in the hippocampus, entorhinal cortex and prefrontal cortex without effects on the rat spatial learning and memory. Environ Res 2014; 134:74-80; PMID:25046815; http://dx.doi.org/10.1016/j.envres.2014.06.025 [] [[PubMed]
- 7. Zhao L, Peng RY, Wang SM, Wang LF, Gao YB, Dung J, Li X, Su ZT. Relationship between cognition function and hippocampus structure after long-term microwave exposure. Biomed Environ Sci 2012; 25:182-8; PMID:22998825 [[PubMed]
- 8. Buchanan RJ, Gjini K, Darrow D, Varga G, Robinson JL, Nadasdy Z. Glutamate and GABA concentration changes in the globus pallidus internus of Parkinson patients during performance of implicit and declarative memory tasks: A report of two subjects. Neurosci Lett 2015; 589:73-8; PMID:25596441; http://dx.doi.org/10.1016/j.neulet.2015.01.028 [] [[PubMed]
- 9. WHO-World Health Organization Environmental health criteria 238: extremely low frequency (ELF) fields. Geneva: WHO Press; c2007. Chapter 1, Summary and recommendations for further study; p. 1-13 [PubMed]
- 10. Cielar G, Mrowiec J, Sowa P, Kasperczyk S, Sieron A Effect of exposure to static, high voltage electric field generated nearby HVDC transmission lines on behavior of rats. In: Progress in Electromagnetics Research Symposium (PIERS 2009 Moscow); 2009 Aug 12–21; Moscow. Cambridge (USA): Electromagnetics Acad; 2009. p. 1097-101 [PubMed]

