Does exposure to extremely low frequency magnetic fields produce functional changes in human brain?

Area of Science:

• Neuroscience
• Biophysics

Background:

• Extremely low frequency magnetic fields (ELF-MF) exposure has been linked to behavioral and neurophysiological changes.
• The underlying physiological mechanisms of ELF-MF effects remain unclear.
• In vitro studies indicate pulsed ELF-MF (PEMFs) can increase excitatory neurotransmission in neuronal cultures.

Purpose of the Study:

• To noninvasively investigate the effects of PEMFs on cortical excitability in humans.
• To assess whether PEMFs modulate glutamatergic activity in the human brain.

Main Methods:

• Transcranial brain stimulation techniques were used in 22 healthy volunteers.
• Paired-pulse stimulation assessed intracortical facilitation and other cortical excitability measures.
• A sham field exposure was conducted in 14 participants for comparison.

Main Results:

• PEMFs exposure significantly increased intracortical facilitation by approximately 20%.
• Other measures of cortical excitability remained unaffected by PEMFs.
• Sham field exposure did not produce any significant changes.

Conclusions:

• PEMFs exposure enhances paired-pulse facilitation, a marker of cortical glutamatergic activity.
• This suggests PEMFs may enhance excitatory neurotransmission in the human brain.
• PEMFs may induce functional alterations in the human brain.