Effects of sinusoidal electromagnetic fields on histopathology and structures of brains of preincubated white leghorn chicken embryos

Abstract

There are several reports indicating linkages between exposures to 50-60 Hz electromagnetic fields and abnormalities in the early stages of chicken embryonic development. Based on our previous published research carried out at the Department of Animal Sciences, Faculty of Biological Sciences, Shahid Beheshti University, effects of sinusoidal electromagnetic fields on histopathology and structures of brains of preincubated white leghorn hen eggs were investigated. Three hundred healthy fresh fertilized eggs (55-65 gr) were divided into three groups of experimental (n = 50), control (n = 75), and sham (n = 75). Experimental eggs (inside the coil) were exposed to 3 different intensities of 1.33, 2.66, and 7.32 mT and sham groups were located inside the same coil with no exposure, for 24 h before incubation. Control, sham, and experimental groups were all incubated in an incubator (38 ± 0.5(°)C, 60% humidity) for 14 days. 14-day old chicken embryos were removed by C-sections, and the brains of all embryos of all groups were fixed in formalin(10%), stained with H&E and TUNEL assay, for studying the histopatholog and process of apoptosis. The brains of other embryos were prepared for Scanning Electeron Microscope. Results showed electromagnetic fields have toxic effects on brain cells by increasing the number of apoptotic cells and degeneration of brains' tissues of exposed chicken embryos. These findings suggest that the electromagnetic fields induce brain damages at different levels.

Correlation between Exposure to Magnetic Fields and Embryonic Development in the First Trimester

“…Most studies of the association between MFs and embryonic development have been performed in chickens or rats and showed that electromagnetic fields had adverse effects on brain cells, with an increased number of apoptotic cells and degeneration of brain tissues of exposed chick or mice embryos [5], [7], [26], [27]. However, exposure levels in animal research have always been higher than those that human populations are exposed to in daily life [24], [28], [29].…”

“…Both in vivo and in vitro studies have shown associations between MFs and adverse health effects that include increased risk of miscarriage [1]–[3], lowered sperm quality [4], and up-regulation genes involved in apoptosis [5]–[7]. However, the biological hazard of MFs remains controversial.…”

Neurodevelopmental anomalies of the hippocampus in rats exposed to weak intensity complex magnetic fields throughout gestation

“…Although minimal or nonsignificant teratogenic effects on the CNS have been reported (Hoyer et al, 2012; Wiley et al, 1992; Yu et al, 1993), it appears that the specific parameters of the applied field (i.e., waveform) may be one of the most important factors to consider in the study of teratogenesis. For instance, sinusoidal or square‐wave pulses can be harmful to CNS growth and development but typically require field strengths on the order of a millitesla or higher to produce reliable effects (Gona et al, 1993; Juutilainen et al, 1986; Lahijani et al, 2011; Sikov et al, 1984; Ubeda et al, 1983). In contrast, we have found that wave‐form patterns whose intrinsic shapes (often asymmetric or irregular pulse patterns) and interstimulus intervals have been designed to simulate common physiological or naturalistic phenomena can also be effective in altering the development of the rat brain even when applied at flux densities several magnitudes lower (<1 μT) (McKay and Persinger, 1999; McKay et al, 2003; St‐Pierre et al, 2008; St‐Pierre and Persinger, 2003, 2008; Whissell et al, 2009).…”