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The Coupling of Atmospheric Electromagnetic Fields

the base of the antennae. In addition, chronic exposure induced change in biogenic amine levels such as

serotonin, dopamine, and octopamine in the brain of fruit fies exposed to the static electric feld of 70

kV/m (Newland et al., 2015).

Jackson et al. go further to analyze the locomotory behavior of cockroaches (Periplaneta americana)

in response to static electric felds of 66–166 kV/m (2011). To analyze the efects of static electric felds on

cockroach behavior, individual cockroaches were placed into the test arena and diferent electric felds

were applied. Walking behavior (such as velocity, distance moved, turn angle, and time spent walking)

were analyzed. It was obtained that the cockroaches turn away or were repulsed when they encountered

an electric feld and if continuously exposed to one, walked more slowly, turned more ofen, and cov­

ered less distance (Jackson et al., 2011). Tis study demonstrated that the behavior of free-moving cock­

roaches is signifcantly infuenced by static electric felds and their responses are related to feld strength.

Te walking activity in cockroaches is also reduced by static electric felds.

Studies of electric feld detection in invertebrates have focused on the direct efects of electrical forces

on sensory limbs such as touch and wings (Bindokas et al., 1989; Newland et al., 2008; Watson, 1984).

Such tactile sensations and wings are related to the sensing of electric feld. Te sensory limbs of insects

are concerned with mechanoreceptors which respond to mechanical disturbances in the insect’s exter­

nal environment, such as contact, extension, and pressure. Te movement of sensory wings by electrical

forces is the same as stimulation by the environment, which leads to activation of mechanoreceptors

and elicits behavioral changers. For example, Bindokas (1989) reported that the wings and sense of touch

of honeybees respond to low-frequency electric felds of 150 kV/m, and wing oscillations in Drosophila

melanogaster occur when exposed to static electric and low-frequency electric felds of 500 kV/m.

Tere are many research studies on the biological efects of the static electric felds, but many papers

do not clarify the electrical conditions. Terefore, we cannot take the results as they are. Te static elec­

tric feld experiments are greatly afected by the material of the used animal cage, the contamination of

the cage, and the relative humidity and temperature in the air, and the magnitude of the electric felds to

which the animals are exposed during experiments difers greatly from the calculated value (Mühleisen,

1966; Shigemitsu et al., 1981). Te high relative humidity prevents charge build-up acting like a Faraday

cage. Terefore, the reliability of the results is considered to be lacking. In the future, the static electric

feld exposure method should be established and the exposure conditions should be standardized.

3.6 Detection of Electromagnetic Fields

In nature, there are dozens of examples of electro- and magneto-receptions. Electro-sensitive species

are able to detect electric felds in order to detect prey and predators, to communicate, and/or locally

orientate. Tese species are also able to respond to magnetic felds, using electro-sensory organs through

the induction laws of Faraday, and some species may have both electro- and magneto-sensing organs.

Electroreception is defned as the ability of an organism to detect weak electric forces. It has long been

known animals living in aquatic conductive environment. Electroreception has been found in sharks,

rays, amphibians, teleost fsh, dolphins, platypuses, etc. Tey use electrosensory organs in their snout

to detect prey in soil.

In mammals, including the human, there exist many types of specifcally developed sensory recep­

tors, such as the rods and cones of the retina that signal light stimuli, the hair cells in the inner ear

that sense sound stimuli, the Pacinian corpuscles in the limbs that detect vibration, the baroceptors

in the aorta that are sensitive to blood pressure changes, and the receptors on the tongue that provide

taste sensation and others. Besides the natural stimuli that elicit activity of each receptor type, electri­

cal stimulation also can activate efectively all of these receptors. Some kinds of fsh, e.g., eel, skate

and shark, possess electroreceptors that are called ampullary lateral line organs. Tese electroreceptors

sense disturbance of electric feld surrounding the fsh (Chichibu, 1970, see Figure 3.12). However, there

is no evidence indicating the existence of specifc receptors in mammalian body that are sensitive solely

to electricity.