Trafficking of synaptic vesicles is changed at the hypothalamus by exposure to an 835 MHz radiofrequency electromagnetic field

2019 · Mixed · Low evidence

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MixedLow evidencePaper 1724

Study snapshot

Publicationmanual · 2019

Study typeanimal

Reported directionMixed

Evidence ratingLow

Abstract

Trafficking of synaptic vesicles is changed at the hypothalamus by exposure to an 835 MHz radiofrequency electromagnetic field Kim JH, Huh YH, Kim HR. Trafficking of synaptic vesicles is changed at the hypothalamus by exposure to an 835 MHz radiofrequency electromagnetic field. Gen Physiol Biophys. 2019 Aug 14. doi: 10.4149/gpb_2019020. Abstract With the rapidly increasing use of mobile phones and their close-contact usage to the brain, there are some concerns about the possible neuronal effects induced by exposure to excessive electromagnetic radiation. Exposure to a radiofrequency electromagnetic field (RF-EMF) of 835 MHz (4.0 W/kg specific absorption rate (SAR) 5 h/day for 12 weeks) may affect hypothalamic presynaptic neurons in C57BL/6 mice. The number and size of the synaptic vesicles (SVs) in the hypothalamic presynaptic terminals were significantly decreased after RF- EMF exposure. Further, the density (SVs numbers/μm) of docking and fusing SVs in the active zones of the presynaptic terminal membrane was significantly decreased in hypothalamic neurons. The expression levels of synapsin I/II and synaptotagmin 1, two regulators of SV trafficking in neurons, were also significantly decreased in the hypothalamus. In parallel, the expression of calcium channel was significantly decreased. These changes in SVs in the active zones may directly decrease the release of neurotransmitters in hypothalamic presynaptic terminals. Therefore, we further studied the possible changes in hypothalamic function by testing the core body temperature and body weight and performed the buried pellet test. The trafficking of SVs was changed by RF- EMF; however, we could not find any significant phenotypical changes in our experimental condition. ncbi.nlm.nih.gov

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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

PopulationC57BL/6 mice

Sample sizeNot supplied

ExposureRF · 835 MHz · 4 W/kg · 5 h/day for 12 weeks

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

After 835 MHz RF-EMF exposure (SAR 4.0 W/kg, 5 h/day for 12 weeks), the number and size of synaptic vesicles and the density of docking/fusing vesicles in hypothalamic presynaptic active zones were significantly decreased in C57BL/6 mice. Synapsin I/II, synaptotagmin 1, and calcium channel expression were also significantly decreased, while no significant changes were observed in core body temperature, body weight, or buried pellet test performance under the experimental conditions.

Outcomes measured

Synaptic vesicle number and size in hypothalamic presynaptic terminals
Density of docking and fusing synaptic vesicles in active zones
Hypothalamic expression of synapsin I/II
Hypothalamic expression of synaptotagmin 1
Hypothalamic expression of calcium channel
Core body temperature
Body weight
Buried pellet test (behavioral/olfactory-related test)

Limitations

Sample size not reported in the provided abstract/metadata
Phenotypic/functional outcomes assessed were limited to body temperature, body weight, and buried pellet test in the abstract
Exposure context described in relation to mobile phone use, but the exposure setup/source is not detailed beyond RF-EMF frequency and SAR

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": 835,
    "sar_wkg": 4,
    "duration": "5 h/day for 12 weeks"
  },
  "population": "C57BL/6 mice",
  "sample_size": null,
  "outcomes": [
    "Synaptic vesicle number and size in hypothalamic presynaptic terminals",
    "Density of docking and fusing synaptic vesicles in active zones",
    "Hypothalamic expression of synapsin I/II",
    "Hypothalamic expression of synaptotagmin 1",
    "Hypothalamic expression of calcium channel",
    "Core body temperature",
    "Body weight",
    "Buried pellet test (behavioral/olfactory-related test)"
  ],
  "main_findings": "After 835 MHz RF-EMF exposure (SAR 4.0 W/kg, 5 h/day for 12 weeks), the number and size of synaptic vesicles and the density of docking/fusing vesicles in hypothalamic presynaptic active zones were significantly decreased in C57BL/6 mice. Synapsin I/II, synaptotagmin 1, and calcium channel expression were also significantly decreased, while no significant changes were observed in core body temperature, body weight, or buried pellet test performance under the experimental conditions.",
  "effect_direction": "mixed",
  "limitations": [
    "Sample size not reported in the provided abstract/metadata",
    "Phenotypic/functional outcomes assessed were limited to body temperature, body weight, and buried pellet test in the abstract",
    "Exposure context described in relation to mobile phone use, but the exposure setup/source is not detailed beyond RF-EMF frequency and SAR"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "radiofrequency electromagnetic field",
    "RF-EMF",
    "835 MHz",
    "specific absorption rate",
    "SAR 4.0 W/kg",
    "hypothalamus",
    "presynaptic terminals",
    "synaptic vesicles",
    "synapsin I/II",
    "synaptotagmin 1",
    "calcium channel",
    "C57BL/6 mice",
    "body temperature",
    "body weight",
    "buried pellet test"
  ],
  "suggested_hubs": [
    {
      "slug": "mobile-phones",
      "weight": 0.85,
      "reason": "Exposure framed around increasing mobile phone use and close-contact brain exposure; RF-EMF at 835 MHz."
    }
  ]
}

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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: 10.4149/gpb_2019020
PubMed: Not supplied

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