Influence of pulsed electromagnetic field with different pulse duty cycles on neurite outgrowth in PC12 rat pheochromocytoma cells.

Bioelectromagnetics · 2005 · Mixed · Low evidence

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MixedLow evidencePaper 5183

Study snapshot

PublicationBioelectromagnetics · 2005

Study typein_vitro

Reported directionMixed

Evidence ratingLow

Abstract

The influence of low frequency (50 Hz repetition rate) pulsed electromagnetic field (EMF) on PC12 cell neurite outgrowth in vitro was investigated in this study. We studied the percentage of neurite bearing cells, average length of neurites, and directivity of neurite outgrowth in PC12 cells cultured for 96 h in the presence of nerve growth factor (NGF). PC12 cells were exposed in one incubator to pulsed EMF at 1.36 mT (peak value) generated by a pair of Helmholtz coils, and the control samples were placed in another identical incubator. We found that the pulse duty cycle had significant effect on neurite outgrowth. Low (10%) pulse on-time significantly inhibited the percentage of neurite bearing cells, but at the same time increased the average length of neurites, while 100% on-time (DC) had exactly the opposite effects. Furthermore, we found that neurites were prone to extend along the direction of pulsed EMF with 10% pulse on-time. Our studies show that neurite outgrowth in PC12 cells is sensitive to the pulse duty and this sensitivity was associated with NGF concentration.

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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 typein_vitro

Effect directionmixed

PopulationPC12 rat pheochromocytoma cells (in vitro) cultured with nerve growth factor (NGF)

Sample sizeNot supplied

ExposureELF · 96 h (cell culture duration during exposure)

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

PC12 cells exposed to a 50 Hz repetition-rate pulsed EMF (1.36 mT peak) showed duty-cycle-dependent changes in neurite outgrowth. A 10% pulse on-time significantly decreased the percentage of neurite-bearing cells but increased average neurite length, whereas 100% on-time (DC) produced the opposite pattern; neurites also tended to extend along the field direction with 10% on-time. The abstract states this sensitivity was associated with NGF concentration.

Outcomes measured

Percentage of neurite-bearing cells
Average neurite length
Directivity (orientation) of neurite outgrowth
Sensitivity/association with NGF concentration

Limitations

In vitro cell model (PC12) may not generalize to in vivo outcomes
Sample size not reported in abstract
Exposure and control were in separate incubators (potential for incubator-related confounding not described)
NGF concentration effects are mentioned but details are not provided in the abstract

View raw extracted JSON

{
  "study_type": "in_vitro",
  "exposure": {
    "band": "ELF",
    "source": "other",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "96 h (cell culture duration during exposure)"
  },
  "population": "PC12 rat pheochromocytoma cells (in vitro) cultured with nerve growth factor (NGF)",
  "sample_size": null,
  "outcomes": [
    "Percentage of neurite-bearing cells",
    "Average neurite length",
    "Directivity (orientation) of neurite outgrowth",
    "Sensitivity/association with NGF concentration"
  ],
  "main_findings": "PC12 cells exposed to a 50 Hz repetition-rate pulsed EMF (1.36 mT peak) showed duty-cycle-dependent changes in neurite outgrowth. A 10% pulse on-time significantly decreased the percentage of neurite-bearing cells but increased average neurite length, whereas 100% on-time (DC) produced the opposite pattern; neurites also tended to extend along the field direction with 10% on-time. The abstract states this sensitivity was associated with NGF concentration.",
  "effect_direction": "mixed",
  "limitations": [
    "In vitro cell model (PC12) may not generalize to in vivo outcomes",
    "Sample size not reported in abstract",
    "Exposure and control were in separate incubators (potential for incubator-related confounding not described)",
    "NGF concentration effects are mentioned but details are not provided in the abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "pulsed electromagnetic field",
    "ELF",
    "50 Hz",
    "duty cycle",
    "PC12 cells",
    "neurite outgrowth",
    "nerve growth factor",
    "Helmholtz coils",
    "1.36 mT",
    "in vitro"
  ],
  "suggested_hubs": []
}

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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: 10.1002/bem.20116
PubMed: 15887254

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