Geophysical Variables and Behavior: Xcix. Reductions in Numbers of Neurons within the Parasolitary Nucleus in Rats Exposed Perinatally to a Magnetic Pattern Designed to Imitate Geomagnetic Continuous Pulsations: Implications for Sudden Infant Death

Infection, Celestial Influences, and Sudden Infant Death Syndrome: A New Paradigm

The etiology of sudden infant death syndrome (SIDS) still remains unclear. This situation would seem unprecedented for 21st-century medical science. This article explores scientific fields that have not been largely considered in investigating the etiology of SIDS so far. In this study, we examined previously ignored studies on heliobiology, celestial influences, and SIDS in the non-medical literature in an attempt to answer the following questions: is there a relationship between sunspot/solar activity and the occurrence of SIDS? Could there be alternative reasons for the decline in SIDS incidences in the 1990s that were originally attributed to the “Back-to-Sleep” campaign? We note that the decline coincided with the ~11-year cyclical diminution in sunspot numbers (SSNs). The SSN/SIDS relationship does not necessarily imply causality; however, it supports published data regarding sunspots, Schumann resonance, and geomagnetic effects. How solar energy could adversely influence a baby’s existence remains conjectural. Observations in this respect suggest pathways involving melatonin and/or infection/inflammation.

Extremely-low frequency magnetic field exposure for simulating geomagnetic pulsations in Alexandrium pacificum and Gymnodinium catenatum cultures

Growth and chain formation in cultures of the chain-forming dinoflagellates Alexandrium pacificum and Gymnodinium catenatum were previously found to be susceptible to space weather variables. A clock drive was used to deliver a frequency of 0.5 Hz and central amplitude of 7 µT in order to perform in vitro simulation of geomagnetic pulsations (composed of extremely low-frequency magnetic fields, ELFMF) which occur during high geomagnetic activity (GMA) periods. Short-term exposure (hours) to this ELFMF increased relative cell growth around 10 nT of naturally occurring GMA. Relative growth outside these intervals gradually approached 0% or was negative for G. catenatum. Differential survival to a subsequent shock was inversely related to growth, and minimal survival coincided with the same 10 nT interval. Relative growth and survival displayed opposite hormetic curves towards GMA: inverted U-shaped for growth, and J-shaped for survival. After exposure to this ELFMF, positive phototaxis response was not lost, but the percentage of cells swimming was slightly reduced. Long-term exposure (days) increased relative growth in A. pacificum but reduced in G. catenatum when low GMA was taking place. These alterations in growth were both associated with a reduction in the cellular pool of mycosporine-like amino acids (MAAs). MAAs that are more susceptible to oxidation were more reduced than those resistant, highlighting that an ELFMF can act by increasing cellular oxidative stress status. The higher susceptibility of G. catenatum found is in compliance with the previous association of its natural populations at the western Iberia coast with periods of solar activity minima and GMA minima.

Effects of electromagnetic fields on reelin and Dab1 expression in the developing cerebral cortex

Many studies describe the biological effects of electromagnetic fields (EMF) including brain damages, neuronal migration and neurogenesis within the central nervous system. Neuronal cell produced in the neuroepithelium migrates along radial glial fibers into the cortical plate. Reelin, which is produced by Cajal-Retzius cells directs neuronal migration. It was shown that Disabled 1 (Dab1) functions downstream of reelin signal transduction pathway that directs the correct cytoarchitecture of the developing cortex. In this study, the EMF effects on total protein concentration (TPC), reelin and Dab1 expression in the developing cortex was studied. 30 pregnant Balb/c mice were separated into three groups: control (n = 10), EMF (n = 10) and SHAM groups (n = 10). The 15-day pregnant mice were placed inside the solenoid for a daily EMF exposure of 5 h for 3 consecutive days (15-17). The SHAM group was also located in the same coil with no exposure. Mice were sacrificed 24 h after the final exposure session. TPC, reelin and Dab1 expression were studied by Bio-Rad protein assay and western blot. No significant change in the TPC was seen in the EMF-treated cerebral cortex samples compared with those from the SHAM and control groups. It was also shown that the reelin and Dab1 expression increases in the EMF-treated cerebral cortex extracts as compared to controls and SHAM group. It is concluded that EMF may play important role in the neural cell migration by increasing reelin and Dab1 expression in the developing cortex.

REDUCED LITTER SIZES FOLLOWING 48-H OF PRENATAL EXPOSURE TO 5 nT TO 10 nT,0.5 HZ MAGNETIC FIELDS: IMPLICATIONS FOR SUDDEN INFANT DEATHS

To test the hypothesis that a narrow intensity band of geomagnetic activity contributes to Sudden Infant Death, 32 pregnant rats were exposed for two to three days before expected parturition either to a coil that generated 0.5 Hz sine-wave, 5 to 10 nanoTesla magnetic fields, or to a reference coil (<1 nT) in the same room. The field was off for 30 min every 4 h during the exposure. The orientation of the coils was perpendicular in space and activated alternately in four blocks of experiments. The litters born to the exposed mothers contained significantly fewer pups (M = 14.1,SD= 2.1) than those exposed to the control conditions (M = 16.2, SD = 2.7). There were significantly fewer numbers of males and fewer numbers of females in litters exposed to the fields generated in the east-west and north-south directions, respectively. These results support the hypothesis that a specific temporal configuration of brief periods of geomagnetic activity can produce an increased incidence of nonvital fetuses, neonates, or infants.

Geomagnetic Activity during the Previous Day is Correlated with Increased Consumption of Sucrose during Subsequent Days: Is Increased Geomagnetic Activity Aversive?

In five separate blocks over a period of several months for 33 female rats the amount of geomagnetic activity during the day before ad libitum access to 10% sucrose or water was positively correlated with the volume of sucrose consumed per 24-hr. period. The strength of the correlation (.62 to .77) declined over the subsequent 10 days from between .12 to –.18 and resembled an extinction curve. In a subsequent experiment four rats exposed to 5 nT to 8 nT, 0.5-Hz magnetic fields that ceased for 30 min. once every 4 hr. for 4 days consumed 11% more sucrose than the four rats exposed to no field. We suggest that the initial consumption of 10% sucrose may have been reinforced because it diminished the aversive physiological effects associated with the increased geomagnetic activity. However, over the subsequent days, as geomagnetic activity decreased or habituation occurred, negative reinforcement did not maintain this behavior.