by a stressor effect of the magnetic field. In a subsequent electronmicroscopic study, Kholodov and his
colleagues demonstrated EMF-induced changes-granular material in the Golgi complex in the rat
pituitary-which seem clearly to be related to increased synthesis, and not a zoonosis (27). Tolgskaya
and colleagues have conducted many studies of the histopathological effects of EMFs (28). In 1973
they described results of a time study of the effects of 3 GHz, 60-320 µW/cm2 (1hr/day for 22 weeks)
on the morphology of the hypothalamus of the rat (29). After 2-3 weeks of exposure there was an
increase in neurosecretory material in cells in the anterior region and along fibers of the
hypothalamohypophysial tract. At 4-5 weeks similar results were seen, but at 22 weeks the picture was
quite different-neurons were smaller with some atrophy, and little secretory material was seen. Six
weeks following termination of exposure the rats exhibited a normal histological appearance.
Behavioral Effects
Most of the major paradigms used in behavioral research have been employed successfully to
establish the existence of EMF-induced behavioral effects. These include studies of spontaneous
activity, reaction time, and conditioned responses.
When motor activity was evaluated by tilt cages, traversal of open-field mazes, or other
ambulatory behaviors, it was found that the responses depended on the characteristics of both the
measuring system and the applied EMFs. Eakin and Thompson (30) used 320-920 MHz, 760 µW/cm2,
for 47 days and found that the exposed rats were more active than the controls during the first 20 days
of exposure, and less active thereafter. These results were confirmed and extended by Eakin in 1970
when hypoactivity was reported following prolonged exposure to 150-430 µW/cm2 (31). Roberti et al.
(32) failed to find an effect due to 3 -10 GHz for 7 days at 1000 µW/cm2,but Mitchelletal. (33),who
exposed rats to 2.45 GHz at about 600 µW/cm2 for 22 days (5 hr/day), found an EMF-induced
hyperactivity in the exposed animals compared to both their pre-exposure baseline and the activity of
sham-exposed controls. The field-induced activity changes in each of these studies were measured
during periods when the animals were removed from the field. When activity was measured during
exposure to a modulated 40-MHz electric field (34), it first increased, then decreased, during the 2-hour
exposure period. This result supported an earlier finding by the same group that the field caused a
similar pattern of change in the emotional response of rats as measured by the Olds self-stimulation
response (35).
The pattem of a dual effect upon performance-stimulation or inhibition, depending on the
circumstances-has not emerged at the low frequencies, most such studies having found only increased
activity. At 1000 v/m, 60 Hz (5 days) (36), and 60,000 v/m, 50 Hz (3 hr) (37), the nocturnal activity of
rodents was increased. An increase in activity in two strains of mice was also seen following exposure
to 17 gauss at 60 Hz (38). Other spontaneous behaviors have been found to be susceptible to EMFs,
including pain-induced aggression (I7), escape (75), avoidance (76-78) and sleep pattern (79).
A standard behavioral measure of a subject's ability to respond to changes in its environment is
its reaction-time to a visual or auditory stimulus. In several studies this has been altered by low-
frequency EMFs. According to Konig and Ankermuller (40), at 1 v/m, 10 Hz and 3 Hz are associated
with a decrease and increase, respectively, in human reaction time as compared to the field-free
situation. In an experimental design in which each subject was exposed to two frequencies in the 2-12
Hz range, at 4 v/m, Hamer found a longer reaction time at the higher frequency (41). Friedman et al.
applied magnetic fields of 0.1 and 0.2 Hz to separate groups of male and female subjects, and for both
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