Extremely low frequency electromagnetic fields promote cognitive function and hippocampal neurogenesis of rats with cerebral ischemia.

Neural regeneration research · 2021 · Benefit · Low evidence

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BenefitLow evidencePaper 5710

Study snapshot

PublicationNeural regeneration research · 2021

Study typeanimal

Reported directionBenefit

Evidence ratingLow

Abstract

Extremely low frequency electromagnetic fields (ELF-EMF) can improve the learning and memory impairment of rats with Alzheimer's disease, however, its effect on cerebral ischemia remains poorly understood. In this study, we established rat models of middle cerebral artery occlusion/reperfusion. One day after modeling, a group of rats were treated with ELF-EMF (50 Hz, 1 mT) for 2 hours daily on 28 successive days. Our results showed that rats treated with ELF-EMF required shorter swimming distances and latencies in the Morris water maze test than those of untreated rats. The number of times the platform was crossed and the time spent in the target quadrant were greater than those of untreated rats. The number of BrdU/NeuN cells, representing newly born neurons, in the hippocampal subgranular zone increased more in the treated than in untreated rats. Up-regulation in the expressions of Notch1, Hes1, and Hes5 proteins, which are the key factors of the Notch signaling pathway, was greatest in the treated rats. These findings suggest that ELF-EMF can enhance hippocampal neurogenesis of rats with cerebral ischemia, possibly by affecting the Notch signaling pathway. The study was approved by the Institutional Ethics Committee of Sichuan University, China (approval No. 2019255A) on March 5, 2019.

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 directionbenefit

PopulationRats with middle cerebral artery occlusion/reperfusion (cerebral ischemia model)

Sample sizeNot supplied

ExposureELF · 5e-05 MHz · 2 hours daily for 28 successive days

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

In a rat cerebral ischemia (middle cerebral artery occlusion/reperfusion) model, ELF-EMF treatment (50 Hz, 1 mT; 2 h/day for 28 days) was associated with improved Morris water maze performance versus untreated rats. Treated rats also showed increased BrdU/NeuN-positive cells in the hippocampal subgranular zone and greater up-regulation of Notch1, Hes1, and Hes5 protein expression.

Outcomes measured

Learning and memory performance (Morris water maze: swimming distance, latency, platform crossings, time in target quadrant)
Hippocampal neurogenesis (BrdU/NeuN cells in subgranular zone)
Notch signaling pathway protein expression (Notch1, Hes1, Hes5)

Limitations

Sample size not reported in the provided abstract/metadata
Animal model; generalizability to humans not addressed in the provided abstract
Exposure source/setup details not described in the provided abstract

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": null,
    "frequency_mhz": 5e-05,
    "sar_wkg": null,
    "duration": "2 hours daily for 28 successive days"
  },
  "population": "Rats with middle cerebral artery occlusion/reperfusion (cerebral ischemia model)",
  "sample_size": null,
  "outcomes": [
    "Learning and memory performance (Morris water maze: swimming distance, latency, platform crossings, time in target quadrant)",
    "Hippocampal neurogenesis (BrdU/NeuN cells in subgranular zone)",
    "Notch signaling pathway protein expression (Notch1, Hes1, Hes5)"
  ],
  "main_findings": "In a rat cerebral ischemia (middle cerebral artery occlusion/reperfusion) model, ELF-EMF treatment (50 Hz, 1 mT; 2 h/day for 28 days) was associated with improved Morris water maze performance versus untreated rats. Treated rats also showed increased BrdU/NeuN-positive cells in the hippocampal subgranular zone and greater up-regulation of Notch1, Hes1, and Hes5 protein expression.",
  "effect_direction": "benefit",
  "limitations": [
    "Sample size not reported in the provided abstract/metadata",
    "Animal model; generalizability to humans not addressed in the provided abstract",
    "Exposure source/setup details not described in the provided abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "ELF-EMF",
    "extremely low frequency",
    "50 Hz",
    "1 mT",
    "cerebral ischemia",
    "middle cerebral artery occlusion",
    "reperfusion",
    "Morris water maze",
    "hippocampal neurogenesis",
    "BrdU/NeuN",
    "Notch signaling",
    "Notch1",
    "Hes1",
    "Hes5"
  ],
  "suggested_hubs": [
    {
      "slug": "animal-studies",
      "weight": 0.9,
      "reason": "Rat model study assessing ELF-EMF effects on cognition and neurogenesis after cerebral ischemia."
    }
  ]
}

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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: 10.4103/1673-5374.301020
PubMed: 33318402

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