Effects of exposure to extremely low frequency electromagnetic fields on hippocampal long-term potentiation in hippocampal CA1 region

2019 · Harm · Low evidence

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HarmLow evidencePaper 1729

Hippocampal slice exposure to ELF magnetic fields (15, 50, 100 Hz; 0.5, 1, 2 mT; 10 s to 5 min) was associated with decreased LTP amplitudes. The decrease was reported to be dose- and duration-dependent, with 15 Hz/2 mT for 5 min producing maximal inhibition …

Study snapshot

Publicationmanual · 2019

Study typeanimal

Reported directionHarm

Evidence ratingLow

Abstract

Effects of exposure to extremely low frequency electromagnetic fields on hippocampal long-term potentiation in hippocampal CA1 region Zheng Y, Cheng J, Dong L, Ma X, Kong Q. Effects of exposure to extremely low frequency electromagnetic fields on hippocampal long-term potentiation in hippocampal CA1 region. Biochem Biophys Res Commun. 2019 Jul 31. pii: S0006-291X(19)31439-1. doi: 10.1016/j.bbrc.2019.07.085. Abstract Exposure to environmental electromagnetic fields, especially to the extremely low-frequency (ELF < 300 Hz) electromagnetic fields (EMFs) might produce modulation effects on neuronal activity. Long-term changes in synaptic plasticity such as long-term potentiation (LTP) involved in learning and memory may have contributions to a number of neurological diseases. However, the modulation effects of ELF-EMFs on LTP are not yet fully understood. In our present study, we aimed to evaluate the effects of exposure to ELF-EMFs on LTP in hippocampal CA1 region in rats. Hippocampal slices were exposed to magnetic fields generated by sXcELF system with different frequencies (15, 50, and 100 Hz [Hz]), intensities (0.5, 1, and 2 mT [mT]), and duration (10 s [s], 20 s, 40 s, 60 s, and 5 min), then the baseline signal recordings for 20 min and the evoked field excitatory postsynaptic potentials (fEPSPs) were recorded. We found that the LTP amplitudes decreased after magnetic field exposure, and the LTP amplitudes decreased in proportion to exposure doses and durations, suggesting ELF-EMFs may have dose and duration-dependent inhibition effects. Among multiple exposure duration and doses combinations, upon 5 min magnetic field exposure, 15 Hz/2 mT maximally inhibited LTP. Under 15 Hz/2 mT ELF-EMFs, LTP amplitude decreases in proportion to the length of exposure durations within 5 min time frame. Our findings illustrated the potential effects of ELF-EMFs on synaptic plasticity and will lead to better understanding of the influence on learning and memory. ncbi.nlm.nih.gov

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeanimal

Effect directionharm

PopulationRats (hippocampal slices; CA1 region)

Sample sizeNot supplied

ExposureELF · 10 s, 20 s, 40 s, 60 s, and 5 min

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Outcomes measured

Hippocampal long-term potentiation (LTP) amplitude
Evoked field excitatory postsynaptic potentials (fEPSPs)

Limitations

Sample size not reported in abstract
Ex vivo hippocampal slice preparation; generalizability to in vivo learning/memory outcomes is not established in abstract
Exposure assessment details beyond frequency/intensity/duration not provided (e.g., waveform, uniformity)

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": "experimental magnetic field exposure (sXcELF system)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "10 s, 20 s, 40 s, 60 s, and 5 min"
  },
  "population": "Rats (hippocampal slices; CA1 region)",
  "sample_size": null,
  "outcomes": [
    "Hippocampal long-term potentiation (LTP) amplitude",
    "Evoked field excitatory postsynaptic potentials (fEPSPs)"
  ],
  "main_findings": "Hippocampal slice exposure to ELF magnetic fields (15, 50, 100 Hz; 0.5, 1, 2 mT; 10 s to 5 min) was associated with decreased LTP amplitudes. The decrease was reported to be dose- and duration-dependent, with 15 Hz/2 mT for 5 min producing maximal inhibition among tested conditions.",
  "effect_direction": "harm",
  "limitations": [
    "Sample size not reported in abstract",
    "Ex vivo hippocampal slice preparation; generalizability to in vivo learning/memory outcomes is not established in abstract",
    "Exposure assessment details beyond frequency/intensity/duration not provided (e.g., waveform, uniformity)"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "extremely low frequency",
    "ELF-EMF",
    "magnetic field",
    "hippocampus",
    "CA1",
    "long-term potentiation",
    "LTP",
    "synaptic plasticity",
    "fEPSP",
    "rat",
    "ex vivo"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.2,
      "reason": "Study concerns ELF magnetic fields (15–100 Hz), which can be relevant to occupational/environmental ELF contexts, though this is an experimental animal-slice study."
    }
  ]
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1016/j.bbrc.2019.07.085
PubMed: Not supplied

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