Study on effect and mechanism of magnetic fields simulating EEG rhythm upon memory.

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference · 2004 · Mixed · Low evidence

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MixedLow evidencePaper 3619

Study snapshot

PublicationConference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference · 2004

Study typeanimal

Reported directionMixed

Evidence ratingLow

Abstract

Magnetic fields simulating EEG rhythm were used to stimulate Wistar rats to explore the effect of magnetic field on retrieval (recall) ability and its mechanism. The results indicated that most of the weak magnetic fields (>10 minutes) simulating the EEG rhythm of human brain impaired the retrieval of long-term memory significantly (P<0.05), but weak magnetic field with special rhythm may even have the capability of facilitating memory performance. And the effects of TMS on memory can last for at least several hours (5h) after TMS. Compared with control group, the release of NE, DA and 5-HT in hippocampus of stimulated group increased (P<0.05); While the release of ACh decreased (P<0.05). Through electronic microscope, morphological changes of nerve synapses in hippocampus of rats were observed after weak magnetic stimulation. The percentage of alpha and beta rhythm in EEG power spectra changed in cats after induced by weak magnetic fields simulating the EEG rhythm.

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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 directionmixed

PopulationWistar rats (also mentions cats for EEG power spectra)

Sample sizeNot supplied

Exposure>10 minutes; effects reported lasting at least 5 hours

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Most weak magnetic fields applied for >10 minutes and simulating human EEG rhythms significantly impaired long-term memory retrieval in Wistar rats (P<0.05), though a special rhythm was reported to potentially facilitate memory performance. Effects on memory were reported to last at least 5 hours after TMS. In stimulated animals, hippocampal NE, DA, and 5-HT release increased and ACh release decreased versus controls (all P<0.05), with synaptic morphological changes observed; in cats, alpha and beta EEG power spectrum percentages changed after exposure.

Outcomes measured

Long-term memory retrieval/recall performance
Neurotransmitter release in hippocampus (NE, DA, 5-HT, ACh)
Hippocampal synapse morphology (electron microscopy)
EEG power spectra (alpha and beta rhythm percentages)

Limitations

No magnetic field parameters (e.g., intensity, waveform details) reported in abstract
No sample sizes or group allocation details reported
Multiple species mentioned (rats and cats) without clear experimental separation in abstract
Unclear which specific rhythms produced impairment versus facilitation

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": null,
    "source": "magnetic field stimulation simulating EEG rhythm (TMS mentioned)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": ">10 minutes; effects reported lasting at least 5 hours"
  },
  "population": "Wistar rats (also mentions cats for EEG power spectra)",
  "sample_size": null,
  "outcomes": [
    "Long-term memory retrieval/recall performance",
    "Neurotransmitter release in hippocampus (NE, DA, 5-HT, ACh)",
    "Hippocampal synapse morphology (electron microscopy)",
    "EEG power spectra (alpha and beta rhythm percentages)"
  ],
  "main_findings": "Most weak magnetic fields applied for >10 minutes and simulating human EEG rhythms significantly impaired long-term memory retrieval in Wistar rats (P<0.05), though a special rhythm was reported to potentially facilitate memory performance. Effects on memory were reported to last at least 5 hours after TMS. In stimulated animals, hippocampal NE, DA, and 5-HT release increased and ACh release decreased versus controls (all P<0.05), with synaptic morphological changes observed; in cats, alpha and beta EEG power spectrum percentages changed after exposure.",
  "effect_direction": "mixed",
  "limitations": [
    "No magnetic field parameters (e.g., intensity, waveform details) reported in abstract",
    "No sample sizes or group allocation details reported",
    "Multiple species mentioned (rats and cats) without clear experimental separation in abstract",
    "Unclear which specific rhythms produced impairment versus facilitation"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "magnetic fields",
    "EEG rhythm simulation",
    "TMS",
    "memory retrieval",
    "long-term memory",
    "hippocampus",
    "norepinephrine",
    "dopamine",
    "serotonin",
    "acetylcholine",
    "synapse morphology",
    "rats",
    "cats"
  ],
  "suggested_hubs": [
    {
      "slug": "animal-studies",
      "weight": 0.9,
      "reason": "Experimental magnetic-field stimulation with behavioral and neurochemical outcomes in animals"
    },
    {
      "slug": "mechanisms-neurotransmitters",
      "weight": 0.6,
      "reason": "Reports changes in hippocampal neurotransmitter release and synaptic morphology"
    }
  ]
}

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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: 10.1109/iembs.2004.1404237
PubMed: 17271293

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