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Changes in synaptic efficacy in rat brain slices following extremely low-frequency magnetic field exposure at embryonic and early postnatal age.

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Balassa T, Varró P, Elek S, Drozdovszky O, Szemerszky R, Világi I, Bárdos G. · 2013

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Magnetic field exposure during brain development caused lasting changes in neural function, suggesting developing brains are particularly vulnerable.

Plain English Summary

Summary written for general audiences

Researchers exposed developing rats to 50 Hz magnetic fields (the same frequency as power lines) during critical brain development periods and found lasting changes in brain function. The exposed animals showed altered electrical activity in brain regions responsible for learning and memory, with some changes persisting weeks after exposure ended. This suggests that magnetic field exposure during early development may affect how the brain processes information later in life.

Why This Matters

This study reveals something particularly concerning about magnetic field exposure during development. The researchers found that exposure levels of 0.5 to 3 milliTesla during critical brain development windows caused measurable changes in synaptic function. To put this in perspective, these exposure levels are higher than typical household exposures but within ranges found near power lines or electrical equipment. What makes this research especially significant is the timing. The brain undergoes rapid development during fetal and early postnatal periods, and this study demonstrates that magnetic fields can interfere with normal neural development processes. The fact that these changes persisted in brain tissue weeks after exposure ended suggests the effects aren't temporary adaptations but potentially permanent alterations to brain circuitry. This adds to a growing body of evidence that the developing nervous system may be particularly vulnerable to EMF exposure, raising important questions about exposure limits for pregnant women and young children.

Exposure Details

Magnetic Field
0.5, 3 mG
Source/Device
50 Hz
Exposure Duration
7 days starting 3 days after birth

Exposure Context

This study used 0.5, 3 mG for magnetic fields:

Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.

Where This Falls on the Concern Scale

Study Exposure Level in ContextA logarithmic scale showing exposure levels relative to Building Biology concern thresholds and regulatory limits.Study Exposure Level in ContextThis study: 0.5, 3 mGExtreme Concern5 mGFCC Limit2,000 mGEffects observed in the Slight Concern range (Building Biology)FCC limit is 4,000x higher than this exposure level

Study Details

The aim of the present study was to determine the effects of a long-term ELF-MF (0.5 and 3 mT, 50 Hz) exposure on synaptic functions in the developing brain.

Rats were treated with chronic exposure to MF during two critical periods of brain development, i.e....

We demonstrated that the basic excitability of hippocampal slices (measured as amplitude of populati...

Results demonstrated that ELF-MF has significant effects on basic neuronal functions and synaptic plasticity in brain slice preparations originating from rats exposed either in fetal or in newborn period.

Cite This Study
Balassa T, Varró P, Elek S, Drozdovszky O, Szemerszky R, Világi I, Bárdos G. (2013). Changes in synaptic efficacy in rat brain slices following extremely low-frequency magnetic field exposure at embryonic and early postnatal age. Int J Dev Neurosci. 31(8):724-730, 2013.
Show BibTeX
@article{t_2013_changes_in_synaptic_efficacy_602,
  author = {Balassa T and Varró P and Elek S and Drozdovszky O and Szemerszky R and Világi I and Bárdos G.},
  title = {Changes in synaptic efficacy in rat brain slices following extremely low-frequency magnetic field exposure at embryonic and early postnatal age.},
  year = {2013},
  
  url = {https://www.sciencedirect.com/science/article/abs/pii/S0736574813001184},
}

Quick Questions About This Study

Researchers exposed developing rats to 50 Hz magnetic fields (the same frequency as power lines) during critical brain development periods and found lasting changes in brain function. The exposed animals showed altered electrical activity in brain regions responsible for learning and memory, with some changes persisting weeks after exposure ended. This suggests that magnetic field exposure during early development may affect how the brain processes information later in life.