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Changes of dendritic spine density and morphology in the superficial layers of the medial entorhinal cortex induced by extremely low-frequency magnetic field exposure.

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Xiong J, He C, Li C, Tan G, Li J, Yu Z, Hu Z, Chen F. · 2013

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Magnetic field exposure at levels found near power lines physically damaged brain cell connections critical for learning and memory in laboratory studies.

Plain English Summary

Summary written for general audiences

Researchers exposed rats to magnetic fields from power lines for up to 28 days and found significant damage to brain cell connections in areas controlling memory and navigation. These structural changes to nerve cells could explain cognitive problems linked to EMF exposure.

Why This Matters

This study provides compelling biological evidence for how EMF exposure might impair cognitive function. The researchers found that 50 Hz magnetic fields at 0.5 mT damaged dendritic spines, the tiny structures that allow brain cells to communicate with each other. What makes this particularly concerning is that the exposure level (0.5 mT or 5 milligauss) is within the range of what people experience near high-voltage power lines or certain electrical appliances. The medial entorhinal cortex, the brain region studied, is crucial for forming spatial memories and helping us navigate our environment. The fact that different types of nerve cells showed varying degrees of vulnerability suggests these effects are complex and potentially cumulative. This research adds important mechanistic support to epidemiological studies that have found associations between EMF exposure and cognitive decline, particularly in children living near power lines.

Exposure Details

Magnetic Field
0.5 mG
Source/Device
50 Hz
Exposure Duration
(14 and 28 days)

Exposure Context

This study used 0.5 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 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

In the present study, we investigated the effects of chronic exposure (14 and 28 days) to a 0.5 mT 50 Hz extremely low-frequency magnetic field (ELM) on the dendritic spine density and shape in the superficial layers of the medial entorhinal cortex (MEC).

We performed Golgi staining to reveal the dendritic spines of the principal neurons in rats.

The results showed that ELM exposure induced a decrease in the spine density in the dendrites of ste...

Considering the changes in spine number and shape are involved in synaptic plasticity and the MEC is a part of neural network that is closely related to learning and memory, these findings may be helpful for explaining the ELM exposure-induced impairment in cognitive functions.

Cite This Study
Xiong J, He C, Li C, Tan G, Li J, Yu Z, Hu Z, Chen F. (2013). Changes of dendritic spine density and morphology in the superficial layers of the medial entorhinal cortex induced by extremely low-frequency magnetic field exposure. PLoS One. 2013 Dec 20; 8(12):e83561. doi: 10.1371/journal.pone.0083561. eCollection 2013.
Show BibTeX
@article{j_2013_changes_of_dendritic_spine_733,
  author = {Xiong J and He C and Li C and Tan G and Li J and Yu Z and Hu Z and Chen F.},
  title = {Changes of dendritic spine density and morphology in the superficial layers of the medial entorhinal cortex induced by extremely low-frequency magnetic field exposure.},
  year = {2013},
  
  url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0083561},
}

Quick Questions About This Study

Researchers exposed rats to magnetic fields from power lines for up to 28 days and found significant damage to brain cell connections in areas controlling memory and navigation. These structural changes to nerve cells could explain cognitive problems linked to EMF exposure.