Andrew A. Marino

Alterations in brain electrical activity caused by magnetic fields: detecting the detection process

Static and 60 Hz magnetic fields, 0.78 gauss, were applied individually and combined to each of 20 human subjects during 2 sec epochs, and the effect on the EEG was determined by comparing the power spectrum obtained during field exposure with that from control epochs. All but one subject exhibited field-induced alterations in the EEG; most subjects exhibited increased EEG activity at 2 or more frequencies within 1-18.5 Hz. The field-induced changes were recorded more often at the central and parietal electrodes than at the occipital electrodes. The responses observed during application of combined static and alternating fields did not differ from the sum of the responses observed when the fields were applied individually, even though the exposure conditions were specifically chosen to favor the hypothesized ion-resonance mechanism of interaction involving Ca2+. The data support the view that detection loci for magnetic fields exist within the nervous system.

Electrical states in the rabbit brain can be altered by light and electromagnetic fields

The effect of low-frequency magnetic fields on the rabbit electroencephalograph (EEG) was studied using a quantitative procedure that permitted statistical evaluation of the response of individual animals. The field conditions used were those predicted by various theories to result in field-animal interactions; light and sham exposure were employed as positive and negative controls, respectively. Sixty-seven percent of the rabbits exhibited changes in the EEG power spectra when light was presented in 2-s epochs; none of the animals responded to sham exposure. When 1 Gauss, 5 Hz, was presented in 2-s epochs, 100% of the animals tested responded to the presence of the field. The rabbits did not respond when the magnetic-field frequency was higher than the physiological range (1-20 Hz) or when it was tuned for resonance of K+. The results showed that an electrical state function may be operationally defined for the rabbit brain, and used to assess the occurrence of an interaction between an animal and external magnetic fields.

EVIDENCE OF A NONLINEAR HUMAN MAGNETIC SENSE

Human subjects respond to low-intensity electric and magnetic fields. If the ability to do so were a form of sensory transduction, one would expect that fields could trigger evoked potentials, as do other sensory stimuli. We tested this hypothesis by examining electroencephalograms from 17 subjects for the presence of evoked potentials caused by the onset and by the offset of 2 G, 60 Hz (a field strength comparable to that in the general environment). Both linear (time averaging) and nonlinear (recurrence analysis) methods of data analysis were employed to permit an assessment of the dynamical nature of the stimulus/response relationship. Using the method of recurrence analysis, magnetosensory evoked potentials (MEPs) in the signals from occipital derivations were found in 16 of the subjects (P<0.05 for each subject). The potentials occurred 109-454 ms after stimulus application, depending on the subject, and were triggered by onset of the field, offset of the field, or both. Using the method of time averaging, no MEPs were detected. MEPs in the signals from the central and parietal electrodes were found in most subjects using recurrence analysis, but no MEPs were detected using time averaging. The occurrence of MEPs in response to a weak magnetic field suggested the existence of a human magnetic sense. In distinction to the evoked potentials ordinarily studied, MEPs were nonlinearly related to the stimulus as evidenced by the need to employ a nonlinear method to detect the responses.

Frequency-specific responses in the human brain caused by electromagnetic fields

The effects of 1.5- and 10-Hz electromagnetic fields (EMFs), 0.2-0.4 gauss, on the intrinsic electrical activity of the human brain at these frequencies was studied. Each of 19 subjects exposed for 2-sec epochs exhibited altered brain electrical activity at the frequency of the EMF during the time of stimulation, as determined by spectral analysis of the electroencephalogram. Since brain activity at specific frequencies could be altered by applied EMFs, the results suggest that it may be possible to use EMFs to determine whether particular intrinsic frequencies subserve specific physiological or behavioral responses.

Electrical treatment of Lewis lung carcinoma in mice.

Direct electrical current of sufficient magnitude and duration can destroy tissue. This capability may be clinically useful in some cases involving inoperable metastatic lesions. In principle, a tumor could be treated with direct current administered via a percutaneous electrode insulated along its entire length except for the portion actually inserted into the tumor. An animal model was developed to study the effect of direct electrical current on tumor growth. The growth of implanted Lewis lung carcinoma in mice was inhibited following the administration of 2 mA for 1 hr, 1-3 treatments. The effect occurred in both small and large tumors. The results suggest that the electrical technique is potentially useful for treating some tumors.

The link between vitamin D metabolism and sleep medicine.

Vitamin D is a hormone that interacts with intranuclear receptors to effect transcriptional changes in many cell types including those in gut, bone, breast, prostate, brain, skeletal muscle, and the immune system. Inadequacy of vitamin D is widely prevalent, and leads to the classic diseases of bone demineralization as well as to more recently recognized problems such as nonspecific pain and noninflammatory skeletal myopathy, which may disrupt sleep and directly cause daytime impairment. Emerging lines of evidence suggest that low vitamin D levels increase the risk for autoimmune disease, chronic rhinitis, tonsillar hypertrophy, cardiovascular disease, and diabetes. These conditions are mediated by altered immunomodulation, increased propensity to infection, and increased levels of inflammatory substances, including those that regulate sleep, such as tumor necrosis factor alpha (TNF-α), interleukin (IL)-1, and prostaglandin D2 (PD2). Together, the recent reports suggest a role for inadequate vitamin D in the development of symptoms of wake impairment commonly associated with sleep disorders. Persistent inadequacy of vitamin D may also increase the risk for obstructive sleep apnea via promotion of adenotonsillar hypertrophy, airway muscle myopathy, and/or chronic rhinitis. Much remains to be learned concerning the complex relationship between chronically low levels of vitamin D, normal sleep, sleep disruption, and daytime neurocognitive impairment.

Effect of low-frequency magnetic fields on brain electrical activity in human subjects

OBJECTIVEnTo measure the response rate of normal human subjects to a low-strength, low-frequency magnetic field (MF), using nonlinear quantitative analysis of the electroencephalogram (EEG).nnnMETHODSnEight subjects were exposed to a series of trials, each consisting of the application of the MF (1 G, 60 Hz) for 2 s followed by a field-free period of 5 s, and the EEG was analyzed statistically using phase-space methods to assess whether the subject detected the MF.nnnRESULTSnEach subject exhibited statistically significant changes in the EEG during presentation of the MF, as evidenced by increases in percent determinism and percent recurrence, two different measures of deterministic structure in the recorded signal, thereby indicating that the MF had been detected.nnnCONCLUSIONSnThe 100% response rate manifested by the study group suggested that the ability to detect low-strength, low-frequency MFs is a common property of the human nervous system.

Low-level EMFs are transduced like other stimuli.

The aims of this study were to test the theory that transduction of low-level electromagnetic fields (EMFs) is mediated like other stimuli, and to determine the false-negative rate of the method used to assess the occurrence of transduction (intra-subject comparison of stimulus and non-stimulus states (ICOS)). A light stimulus was chosen as a basis of comparison because light could be applied and removed at precise time points, similar to the manner in which EMFs were controlled. Subjects exposed to a weak light stimulus during 2-second epochs exhibited alterations in brain electrical activity that were similar to those previously observed in subjects exposed to EMFs. The false-negative rate of the ICOS method was 61%, since it registered an effect in only 39% of the subjects (11/28) whereas all subjects were actually aware of the light. In a second group of subjects that were exposed to 0.8 G (1.5 or 10 Hz), 58% (11/19) exhibited similar alterations in brain activity, as determined using ICOS. Previous measurements in the same subjects using a different method showed that the EMFs actually affected brain electrical activity in all subjects; consequently, the false-negative rate was 42% when an EMF was used as the stimulus. The results suggested that the post-transduction brain electrical processes in human subjects were similar in the cases of EMF and light stimuli, as hypothesized, and that the high negative rate of the ICOS method (here and in previous studies) was composed partly or entirely of false-negative results.

Electromagnetic fields, cancer, and the theory of neuroendocrine-related promotion

Environmental electromagnetic fields were predicted to increase the risk for cancer in chronically exposed human subjects because of impaired immunosurveillance mediated by the neuroendocrine system. This theory was examined by evaluating the human observational studies involving EMF-exposed subjects, and it was determined that the risk of cancer is greater when EMFs are added to the environment, at least for children and white males. The inference of risk obtained from the studies supports the theory of neuroendocrine-related progression of cancer but does not prove it because the studies provide no basis to exclude other possible mechanisms such as EMF-induced changes in ornithine decarboxylase, melatonin, or ion-resonance interactions.

Electrochemical modification of tumor growth in mice

We evaluated the effect of direct electrical current on large tumors in mice. Lewis lung carcinoma greater than 1 cm in the shortest dimension was treated percutaneously with 20 mA for 15 min. Separate groups were given one or more than one (two or three) percutaneous electrical treatments (PET). A third group was given sham electrical treatment, and a fourth group had surgical excision of the tumor. Animals in both PET groups survived longer and had smaller primary tumors at death compared with the sham group. PET did not alter the systemic course of the disease, judged by lung and spleen weights and by histological observation of the extent of metastatic burden in the lung. Surgery resulted in long-term survival of 17% and an increase in average survival time compared with both PET and sham treatment. PET produced rapid and polarity-dependent alterations in physiological solutions in vitro, and it is likely that similar electrochemical processes mediated the observed reduction in tumor growth. PET is potentially useful as an adjuvant modality because it reduces local tumor mass but does not alter the extent of metastasis.