A Case Study: Tapping the Bioinitiative Website

This post will introduce our readers to the BioInitiative website, which makes publications on electromagnetic fields (EMF) and radiofrequency radiation (RF) on health topics accessible. The information is set up to allow users to integrate the EMF and RF information on health into their own practices. I hope other CHE groups will begin to consider how EMF and RF studies, along with other important environmental contaminants, can shape our views on the etiologies of breast cancer, brain cancers, heart disease, neurological diseases, cognitive and neurodevelopmental problems like autism and ADHD, and the fundamental mechanisms involved.

The Bioinitiative provides broad information the science and public health consequences of EMF and wireless technologies. This website offers an opportunity for CHE members to access many hundreds of scientific abstracts on EMF and RF. The Research Summaries can be downloaded and word-searched by topic or keyword ("hippocampus", for example). The ability to quickly access scientific publications reporting effects (or no effects) is a vital part of research and education. This collection offers rapid access to decision-makers and the public on the state of the evidence for EMF and RF effects on human health. It can help researchers identify common pathways, mechanisms and biomarkers that may overlap with chemical and ionizing radiation, and studies of various disease endpoints (cancers, neurological diseases, neurodevelopmental problems and more).

A CHE ScienceServ that I follow recently included a post regarding a new study of hippocampal activation, increased amyloid accumulation and cognitive decline.¹ I was able to search the Bioinitiative website for studies on effects of radiofrequency and microwave radiation on the hippocampus and found 44 studies reporting effects on the hippocampus from exposure to radiofrequency radiation, primarily in the cell phone and Wi-Fi frequency ranges. RF/microwave exposures are clearly biologically active in the hippocampus at exposure levels below current safety limits. Such exposures are reported to cause changes in development, structure and function of the hippocampus.

The studies I located provide readers a sense of the scope of information available on the Bioinitiative website:

• Lai et al, 1991: An increase in receptor concentration occurred in the hippocampus of rats subjected to ten 45-min sessions of microwave exposure, whereas a decrease in concentration was observed in the frontal cortex and hippocampus of rats exposed to ten 20-min sessions.²
• Lai et al, 1992: The data showed that all three subtypes of opioid receptors are involved in the microwave-induced decrease in cholinergic activity in the hippocampus.³
• Grigor'ev et al, 1995: The reaction of hippocampus was displayed as amplification of theta-range in spectrum within of normal functioning.⁴
• Lai et al, 1996: These data indicate that mu-opioid receptors in the septum mediate a microwave-induced decrease in cholinergic activity in the hippocampus and support our hypothesis that microwaves at a whole body SAR of 0.6 W/kg can activate endogenous opioids in the brain.⁵
• Pu et al, 1997: Adenosine triphosphate (ATP) in the brain and the amounts of succinate dehydrogenase (SDH) in the hypothalamus and hippocampus were reduced significantly in the group irradiated at 3000-MHz microwave 1 h daily for 7 days as compared to the control.⁶
• Ding et al, 1998: Decrease of nitric oxide synthase expression in hippocampus relates to the obstruction of learning and memory of the rat after exposure to electromagnetic pulse.⁷
• Wu et al, 1999: Electromagnetic pulse exposure results in changes of the content of neurotransmitters in different cerebral areas of rats, lowering their ability of learning.⁸
• Cobb et al, 2000: The medial-to-lateral length of the hippocampus was significantly longer in the ultra-wideband electromagnetic fields -exposed pups than in the sham-exposed animals.⁹
• Tattersall et al, 2001: Low-intensity RF fields can modulate the excitability of hippocampal tissue in vitro in the absence of gross thermal effects.¹⁰
• Testylier et al, 2002: Neurochemical modification of the hippocampal cholinergic system can be observed during and after an exposure for 1 h during the day to a 2.45 GHz continuous wave radiofrequency field (RF).¹¹
• Salford et al, 2003: We found highly significant (p<0.002) evidence for neuronal damage in the cortex, hippocampus, and basal ganglia in the brains of rats exposed for 2 hr to Global System for Mobile Communications (GSM) mobile phone electromagnetic fields of different strengths.¹²
• Paulraj & Behari, 2004: A significant decrease in the calcium-dependent protein kinase C (PKC) enzyme level was observed in the modulated radio frequency (RF) radiation exposed group as compared to the sham exposed group.¹³
• Koylu et al, 2006: The levels of lipid peroxidation in the brain cortex and hippocampus increased in the microwave-exposed (MW) group compared with the control group, although the levels in the hippocampus were decreased by MW+melatonin administration.¹⁴
• Lopez-Martin et al, 2006: When rats transformed into an experimental model of seizure-proneness by acute subconvulsive doses of picrotoxin were exposed to 2 h GSM-modulated 900 MHz radiation at an intensity similar to that emitted by mobile phones, they suffered seizures and the levels of the neuronal activity marker c-Fos in neocortex, paleocortex, hippocampus and thalamus increased markedly.¹⁵
• Paulraj & Behari, 2006: Our study reveals a statistically significant decrease in protein kinase C activity in hippocampus in the group exposed to 2.45 GHz radiation for 2 h/day for a period of 35 days as compared to the remaining portion of the whole brain and the control group.¹⁶
• Zhao et al, 2006: Map2 was statistically significantly up-regulated after neurons were exposed to the RF EMF.¹⁷
• Ammari et al, 2008: Our results indicated that chronic exposure to GSM 900 MHz microwaves may induce persistent astroglia activation in the rat brain (sign of a potential gliosis).¹⁸
• Nittby et al, 2008: Gene ontology analysis (using the gene ontology categories biological processes, molecular functions, and cell components) of the differentially expressed genes of the exposed animals versus the control group revealed the following highly significant altered gene categories in both cortex and hippocampus: extracellular region, signal transducer activity, intrinsic to membrane, and integral to membrane.¹⁹
• Odaci et al, 2008: Prenatal EMF exposure caused a decrease in the number of granule cells in the dentate gyrus of the hippocampus rat brain.²⁰
• Bas et al, 2009: Postnatal EMF exposure caused a significant decrease of the hippocampal pyramidal cell number in the cornu ammonis (CA) of the EMF group. Additionally, cell loss can be seen in the CA region of EMF group even at qualitative observation.²¹
• Daniels et al, 2009: We found no significant differences in the spatial memory test, and morphological assessment of the brain also yielded non-significant differences between the groups. However, in some exposed animals there were decreased locomotor activity, increased grooming and a tendency of increased basal corticosterone levels.²²
• Kesari & Behari, 2009: With chronic exposure to these radiations, PKC decreased significantly in whole brain and hippocampus and DNA double-strand break (head and tail length, intensity and tail migration) and showed a significant decrease in glutathione peroxidase and superoxides dismutase activity in brain cells, whereas catalase activity shows significant increase in the exposed group of brain samples as compared with control.²³
• Li et al, 2009: Microwave radiation can increase the expression of AQP4 in rat hippocampus.²⁴
• Ammari et al, 2010: Sub-chronic exposures to a 900 MHz EMF signal for two months could adversely affect rat brain, including the dentate gyrus of the hippocampus (sign of a potential gliosis).²⁵
• Maskey et al, 2010: Exposure for 1 month produced almost complete loss of hippocampal pyramidal cells in the CA1 area.²⁶
• Narayanan et al, 2010: Mobile phone RF-EMR exposure significantly altered the passive avoidance behaviour and hippocampal morphology in rats.²⁷
• Carballo-Quintás et al, 2011: Ninety minutes after radiation high levels of c-fos expression were recorded in the neocortex and paleocortex along with low hippocampus activation in picrotoxin treated animals. Most brain areas, except the limbic cortical region, showed important increases in neuronal activation 24 h after picrotoxin and radiation.²⁸
• Dragicevic et al 2011: These results collectively suggest that brain mitochondrial enhancement may be a primary mechanism through which EMF treatment provides cognitive benefit to both transgenic and non-transgenic mice.²⁹
• Fragopoulou et al, 2012: Comparative proteomics analysis revealed that long-term irradiation from two EMF sources—a typical mobile phone and a wireless DECT base (Digital Enhanced Cordless Telecommunications/Telephone)—altered significantly (p<0.05) the expression of 143 proteins in total (as low as 0.003-fold downregulation up to 114-fold overexpression).³⁰
• Lu et al, 2012: Our results indicate that glucose administration attenuates the spatial memory deficits induced by chronic low-power-density microwave (MW) exposure, and reduced hippocampal glucose uptake may be associated with cognitive impairment caused by MW exposure.³¹
• Yang et al, 2012: Exposure to electromagnetic fields elicits a stress response in the rat hippocampus.³²
• Aboul Ezz et al, 2013: The exposure to electromagnetic radiation (EMR) resulted in significant changes in dopamine, norepinephrine and serotonin in the four selected areas of adult rat brain, including the hippocampus and hypothalamus.³³
• İkinci et al, 2013: The application of a 900 MHz EMF in the prenatal period adversely affected female pups' learning behavior and also resulted in histopathological changes appearing in the hippocampus.³⁴
• Ntzouni et al 2013: The data suggest that visual information processing mechanisms in hippocampus, perirhinal and entorhinal cortex are gradually malfunctioning upon long-term daily exposure to GSM 1.8 GHz signal for 90 min daily by a typical cellular (mobile) phone, a phenotype that persists for at least 2 weeks after interruption of radiation, returning to normal memory performance levels 4 weeks later.³⁵
• Tong et al, 2013: Electromagnetic radiation may cause structure and function changes of transfer synaptic in global, make hippocampal CA1 area neurons change in the overall discharge characteristic and discharge patterns, thus lead to decrease in the ability of learning and memory.³⁶
• Wang et al, 2013: This study suggested that impairment of long-term potentiation induction and the damages of hippocampal structure, especially changes of synapses, might contribute to cognitive impairment after microwave exposure.³⁷
• Ghazizadeh & Nazıroğlu, 2014: Epilepsy and Wi-Fi in our experimental model is involved in Ca(2+) influx and oxidative stress-induced hippocampal and DRG death through activation of TRPV1 channels, and negative modulation of this channel activity by capsazepine pretreatment may account for the neuroprotective activity against oxidative stress.³⁸
• Li et al, 2014: The results suggested that in the long-term way, chronic microwave exposure could induce cognitive deficit and 5-HT system may be involved in it, as degeneration of hippocampal neurons was observed.³⁹
• Saikhedkar et al, 2014: After exposure to 900 MHz radio waves by means of a mobile hand set for 4 hours per day for 15 days, increased production of reactive oxygen species due to exhaustion of enzymatic and non-enzymatic antioxidants and increased lipid peroxidation indicate extensive neurodegeneration in selective areas of CA1, CA3, DG, and the cerebral cortex were evident. This extensive neuronal damage results in alterations in behavior related to memory and learning. Histological examination showed neurodegenerative cells in hippocampal sub regions and cerebral cortex.⁴⁰
• Megha et al, 2015: Results showed significant reduction in levels of dopamine, norepinephrine, epinephrine and 5-HT in hippocampus of microwave-exposed animals in comparison with sham-exposed (control) animals.⁴¹
• Şahin et al, 2015: Stereological analyses showed that the total number of hippocampal pyramidal neurons in the cornu ammonis of the EMF exposed rats was significantly lower than those in the control and the sham exposed groups.⁴²
• Tang et al, 2015: Exposure to 900 MHz EMF radiation for 28 days can significantly impair spatial memory and damage blood brain barrier permeability which resulted in albumin and HO-1 extravasation observed in the hippocampus and cortex in rats by activating the mkp-1/ERK pathway.⁴³
• Wang et al, 2015: This study indicated that the content of amino acids neurotransmitters, the expression of NMDAR subunits and the variation of hippocampal structure might contribute to the long-term cognitive impairment after microwave exposure.⁴⁴
• Xiong et al, 2015: 30 mW/cm² microwave exposure caused injury in rat hippocampal structure and PC12 cells, especially the structure and quantity of synapses, amino acid neurotransmitter release and calcium influx.⁴⁵

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45. Xiong L, Sun CF, Zhang J, Gao YB, Wang LF, Zuo HY, Wang SM, Zhou HM, Xu XP, Dong J, Yao BW, Zhao L, Peng RY. Microwave exposure impairs synaptic plasticity in the rat hippocampus and pc12 cells through over-activation of the NMDA receptor signaling pathway. Biomedical and Environmental Sciences. 2015 Jan;28(1):13-24.

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