Neural and behavioral teratological evaluation of rats exposed to ultra-wideband electromagnetic fields

Abstract

Several investigators have reported teratologic effects of electromagnetic field exposure. The majority of these studies have been performed at levels of exposure that could produce substantial heating of the animals. New and unique sources of ultra-wideband (UWB) electromagnetic fields are currently being developed and tested that are capable of generating nonthermalizing, high-peak-power, microwave (MW) pulses with nanosecond (ns) pulse widths, picosecond (ps) rise times, and an UWB of frequencies. Our study was performed to determine if teratological changes occur in rat pups as a result of (i) daily UWB exposures during gestation days 3-18, or (ii) as a result of both prenatal and postnatal (10 days) exposures. Dams were exposed either to (i) UWB irradiation from a Kentech system that emitted a 55 kV/m-peak E field, 300 ps rise time, and a 1.8 ns pulse width, average whole-body specific absorption rate 45 mW/kg; (ii) sham irradiation; or (iii) a positive control, lead (Pb) acetate solution (2000 microg/ml) continuously available in the drinking water. Offspring were examined for ontogeny (litter size, sex-ratios, weights, coat appearance, tooth-eruption, eye-opening, air-righting, and ultrasonic stress vocalizations). Male pups were tested on various performance measures (locomotor, water-maze learning, and fertilization capabilities). The pups postnatally exposed were examined for hippocampal morphology and operant behavior. Behavioral, functional, and morphological effects of UWB exposure were unremarkable with these exceptions: (i) The UWB-exposed pups emitted significantly more stress vocalizations than the sham-exposed pups; (ii) the medial-to-lateral length of the hippocampus was significantly longer in the UWB-exposed pups than in the sham-exposed animals; (iii) male offspring exposed in utero to UWB mated significantly less frequently than sham-exposed males, but when they did mate there was no difference in fertilization and offspring numbers from the sham group. There does not appear to be a unifying physiological or behavioral relationship among the significant differences observed, and our findings could be due to the expected spurious results derived when a large number of statistical comparisons are made. Significant effects found between our positive-controls and other groups on numerous measures indicates that the techniques used were sensitive enough to detect teratological effects. Bioelectromagnetics 21:524-537, 2000. Published 2000 Wiley-Liss, Inc.

Strength-Duration Curve for an Electrically Excitable Tissue Extended Down to Near 1 Nanosecond

“…Eight papers reported negative results. The diverse endpoints examined, in studies using rats, include behavioral teratology [6], regulation of heart rate and blood pressure [7], [8], chemically induced convulsions [9], and behavior, hematology, and brain histology [10]. In addition, a behavioral study in primates [11], plus genetic studies in mice [12] and yeast [13], found no effects of UWB exposure.…”

“…To change the published SAR value data to a peak, rather than an rms value, the 0.4 W/kg per 1 was multiplied by a factor of 2. The factor normally used to change rms to peak was squared, because the electrical field stimulus is squared in (6).…”

Nuclear Translocation and DNA-Binding Activity of NFKB (NF-κB) after Exposure of Human Monocytes to Pulsed Ultra-wideband Electromagnetic Fields (1 kV/cm) Fails to Transactivate κB-Dependent Gene Expression

“…d.c. to 2 GHz), rise times of less than 1 ns to several nanoseconds, and pulse durations from 1 ns to microseconds. The literature on the possible biological effects of exposure to pulsed EMFs is limited and has frequently focused on the measurement of behavioral alterations after exposure of animal models (1)(2)(3)(4)(5)(6)(7). Few studies have attempted to observe basic responses at subcellular levels after such exposures (8).…”

Neonatal Ethanol Exposure but not Neonatal Cocaine Selectively Reduces Specific Isolation-Induced Vocalization Waveforms in Rats

“…Not surprisingly, a variety of prenatal insults can also alter the frequency of USVs including prenatal stress (Morgan et al, 1999), nitrogen (Di Giovanni et al, 1994), electromagnetic fields (Cobb et al, 2000), methylmercury (Elsner et al, 1990) and possibly ethanol (Kehoe and Shoemaker, 1991). With the reliability of this behavior and the relative ease that one can examine it, isolation-induced USVs are currently used as a component of behavioral test screens for potential teratogenicity or developmental toxicity (Adams et al, 1983;Branchi et al, 2001).…”