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Electromagnetic Fields in Biological Systems
Novikov, Sheiman, and Fesenko (2008) studied the effects of weak static (direct
current [DC]) and alternating (alternating current [AC]) magnetic fields, as well as combined (AC–DC) collinear magnetic fields, on the intensity of morphogenesis processes
in the planarian Dugesia tigrina. The authors found that combined magnetic fields (e.g.,
42-μT DC + 3.7 Hz 100-nT AC) produced a stimulating effect on the fission and regeneration of planarians. The exposure to “zero” field also induced significant stimulating
effects comparable with those produced by combined magnetic fields in the effective
range. In contrast, AC fields alone produced inhibitory effect. The authors speculated
that the effects observed may be of great importance in analyzing the mechanisms of
action of weak and superweak fields on living organisms.
From another aspect, Muehsam and Pilla (2009a,b) proposed a Lorenz model for
weak magnetic field bioeffects, suggesting that weak, exogenous AC–DC magnetic fields
can act on an ion or ligand bound in a molecular cleft, based on the assumption that the
receptor molecule is able to detect the Larmor trajectory of an ion or ligand within the
binding site. To date, however, there is insufficient direct experimental evidence pertaining to this model. Further studies are required to decipher and better understand the
mechanisms of the bioeffects of DC magnetic fields (SMF).
Zhang et al. (2004) applied Drosophila to the study of learning and memory to investigate the removal effect of the geomagnetic field for successive generations of living
organisms. Using the operant visual learning/memory paradigm in a flight simulator,
this study revealed that wild-type flies raised in a hypomagnetic field environment
continuously for 10 successive generations became gradually impaired in visual conditioning learning and memory formation; finally, the tenth generation flies became
morphs of nonlearners and completely amnesiac. The control experiments show that the
impairment cannot be ascribed to any apparent sensorimotor problems in Drosophila.
The reverse shift from hypomagnetic field to natural geomagnetic field learning and
memory ability following six consecutive generations. Thus, these findings demonstrate
conclusively that some serious, but reversible, learning and memory impairments may
occur in living organisms as a result of a prolonged separation from the geomagnetic
field over many consecutive generations.
Hung et al. (2010) investigated the effects of SMFs of up to 200 mT on the developmental and aging processes of Caenorhabditis elegans. Treatment with a 200-mT SMF
reduced the development time from L2 to L3 stage by 20%, from L3 to L4 by 23%, and
from L4 to young adult by 31%. After SMF exposure, the average life span was reduced
from 31 days to 24 days for wild-type nematodes. The upregulation of the clock genes
clk-1, lim-7, daf-2, unc-3, and age-1 after SMF treatment was verified by quantitative realtime Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Apparently, induction of gene expression is selective and dose dependent. The total developmental time
was significantly reduced for the lin-4, lin-14, lin-41, and lin-7 mutants, but not for the
let-7, clk-1, unc-3, and age-1 mutants. Life span analyses revealed that the let-7, unc-3,
and age-1 mutants were not affected by SMF exposure. The authors and, thereafter, Lee,
Hung, and Huang (2010) suggest that the SMF accelerated nematode development and
shortened nematode life span through pathways associated with the let-7, clk-1, unc-3,
and age-1 mutants.
Electromagnetic Fields in Biological Systems
Novikov, Sheiman, and Fesenko (2008) studied the effects of weak static (direct
current [DC]) and alternating (alternating current [AC]) magnetic fields, as well as combined (AC–DC) collinear magnetic fields, on the intensity of morphogenesis processes
in the planarian Dugesia tigrina. The authors found that combined magnetic fields (e.g.,
42-μT DC + 3.7 Hz 100-nT AC) produced a stimulating effect on the fission and regeneration of planarians. The exposure to “zero” field also induced significant stimulating
effects comparable with those produced by combined magnetic fields in the effective
range. In contrast, AC fields alone produced inhibitory effect. The authors speculated
that the effects observed may be of great importance in analyzing the mechanisms of
action of weak and superweak fields on living organisms.
From another aspect, Muehsam and Pilla (2009a,b) proposed a Lorenz model for
weak magnetic field bioeffects, suggesting that weak, exogenous AC–DC magnetic fields
can act on an ion or ligand bound in a molecular cleft, based on the assumption that the
receptor molecule is able to detect the Larmor trajectory of an ion or ligand within the
binding site. To date, however, there is insufficient direct experimental evidence pertaining to this model. Further studies are required to decipher and better understand the
mechanisms of the bioeffects of DC magnetic fields (SMF).
Zhang et al. (2004) applied Drosophila to the study of learning and memory to investigate the removal effect of the geomagnetic field for successive generations of living
organisms. Using the operant visual learning/memory paradigm in a flight simulator,
this study revealed that wild-type flies raised in a hypomagnetic field environment
continuously for 10 successive generations became gradually impaired in visual conditioning learning and memory formation; finally, the tenth generation flies became
morphs of nonlearners and completely amnesiac. The control experiments show that the
impairment cannot be ascribed to any apparent sensorimotor problems in Drosophila.
The reverse shift from hypomagnetic field to natural geomagnetic field learning and
memory ability following six consecutive generations. Thus, these findings demonstrate
conclusively that some serious, but reversible, learning and memory impairments may
occur in living organisms as a result of a prolonged separation from the geomagnetic
field over many consecutive generations.
Hung et al. (2010) investigated the effects of SMFs of up to 200 mT on the developmental and aging processes of Caenorhabditis elegans. Treatment with a 200-mT SMF
reduced the development time from L2 to L3 stage by 20%, from L3 to L4 by 23%, and
from L4 to young adult by 31%. After SMF exposure, the average life span was reduced
from 31 days to 24 days for wild-type nematodes. The upregulation of the clock genes
clk-1, lim-7, daf-2, unc-3, and age-1 after SMF treatment was verified by quantitative realtime Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Apparently, induction of gene expression is selective and dose dependent. The total developmental time
was significantly reduced for the lin-4, lin-14, lin-41, and lin-7 mutants, but not for the
let-7, clk-1, unc-3, and age-1 mutants. Life span analyses revealed that the let-7, unc-3,
and age-1 mutants were not affected by SMF exposure. The authors and, thereafter, Lee,
Hung, and Huang (2010) suggest that the SMF accelerated nematode development and
shortened nematode life span through pathways associated with the let-7, clk-1, unc-3,
and age-1 mutants.