Cellular apoptosis and blood brain barrier permeability changes in the pre-incubated chicken embryo's brain by effect of electromagnetic fields

ABSTRACT

Electromagnetic fields [EMF] have teratogenic effects during the embryonic development. In current study, histopathological and physiological effects of sinusoidal EMF on the brain were investigated. We sought to determine the apoptosis level and changes in blood brain barrier permeability in brain tissue of pre-incubated white leghorn hen eggs in the field of EMF. In this experimental study, 300 healthy, fresh, and fertilized eggs [55-65 g] were divided into experimental [3 groups, N=50], control [N=75] and sham [N=75] groups. Experimental eggs [inside the coil] were exposed to 3 different intensities of 1.33, 2.66 and 7.32 mT and sham groups were also located inside the same coil but with no exposure, for 24 hrs before incubation. Control, sham and experimental groups were incubated in an incubator [38 +/- 0.5[degree]C, 60% humidity]. Brains of 14-day old chicken embryos of all groups were removed, fixed in formalin [10%], stained with H and E and TUNEL, apoptotic cells were studied under light microscope. Brains of other embryos were prepared for scanning electron microscope. By injections of Evans blue, any possible changes in brain vessels were also investigated. Our results showed electromagnetic fields have toxic effects on cell organelles and cell membranes. EMF would increase the level of cellular apoptosis in the brain. They also would tear up the blood vessels. Thereafter, they would affect the permeability of blood brain barrier of exposed chicken embryos. These findings suggest that electromagnetic fields induce different degrees of brain damages in chicken embryos brain tissue