Changes in cognitive function, synaptic structure and protein expression after long-term exposure to 2.856 and 9.375 GHz microwaves

2023 · Harm · Low evidence

← Research stream

HarmLow evidencePaper 561

Study snapshot

Publicationmanual · 2023

Study typeanimal

Reported directionHarm

Evidence ratingLow

Abstract

Changes in cognitive function, synaptic structure and protein expression after long-term exposure to 2.856 and 9.375 GHz microwaves Wang H, Liu Y, Sun Y, Dong J, Xu X, Wang H, Zhao X, Zhang J, Yao B, Zhao L, Liu S, Peng R. Changes in cognitive function, synaptic structure and protein expression after long-term exposure to 2.856 and 9.375 GHz microwaves. Cell Commun Signal. 2023 Feb 13;21(1):34. doi: 10.1186/s12964-022-01011-1. Abstract Health hazards from long-term exposure to microwaves, especially the potential for changes in cognitive function, are attracting increasing attention. The purpose of this study was to explore changes in spatial learning and memory and synaptic structure and to identify differentially expressed proteins in hippocampal and serum exosomes after long-term exposure to 2.856 and 9.375 GHz microwaves. The spatial reference learning and memory abilities and the structure of the DG area were impaired after long-term exposure to 2.856 and 9.375 GHz microwaves. We also found a decrease in SNARE-associated protein Snapin and an increase in charged multivesicular body protein 3 in the hippocampus, indicating that synaptic vesicle recycling was inhibited and consistent with the large increase in presynaptic vesicles. Moreover, we investigated changes in serum exosomes after 2.856 and 9.375 GHz microwave exposure. The results showed that long-term 2.856 GHz microwave exposure could induce a decrease in calcineurin subunit B type 1 and cytochrome b-245 heavy chain in serum exosomes. While the 9.375 GHz long-term microwave exposure induced a decrease in proteins (synaptophysin-like 1, ankyrin repeat and rabankyrin-5, protein phosphatase 3 catalytic subunit alpha and sodium-dependent phosphate transporter 1) in serum exosomes. In summary, long-term microwave exposure could lead to different degrees of spatial learning and memory impairment, EEG disturbance, structural damage to the hippocampus, and differential expression of hippocampal tissue and serum exosomes. Excerpts ... There were no significant increases in rectal temperature (p = 0.1000, p = 0.128, p = 0.104) between the time points before and immediately after microwave exposure in any group, indicating that the effects of microwave radiation on the mice in this experiment were mainly nonthermal effects (Fig. 1C).... The radiation duration in this study was based on the ICNIRP guidelines for Limiting Exposure to Electromagnetic Fields (2020 version), which established a standard time interval of 6 min for head health threats. Therefore, 6 min was used as a daily exposure time to explore the effects. Moreover, to determine whether the thermal effect played a role in the exposure period, a core temperature detection method was used in our study according to the previous literature [30]. The experimental results indicated that nonthermal effects were mainly involved in our study.... In summary, long-term microwave exposure (2.856 and 9.375 GHz, 6 min/d, 5 d/w, 6 w) led to different degrees of spatial learning and memory impairment, EEG disturbance, damage to hippocampal structure and differential expression of hippocampal tissue and serum exosomes. The SNARE-associated protein Snapin and charged multivesicular body protein 3 in the hippocampus could be used as sensitive markers of microwave exposure, and synaptic vesicle recycling was inhibited by long-term microwave exposure. Different proteins in serum exosomes were found after exposure to different frequency microwaves. Open access paper: biosignaling.biomedcentral.com

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

PopulationMice

Sample sizeNot supplied

Exposuremicrowave · 6 min/day, 5 days/week, 6 weeks (long-term exposure); frequencies 2.856 and 9.375 GHz

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

After long-term exposure to 2.856 and 9.375 GHz microwaves, spatial reference learning and memory and DG-area structure were reported as impaired, with EEG disturbance and hippocampal structural damage. The study reports decreased hippocampal Snapin and increased charged multivesicular body protein 3, and frequency-specific decreases in several proteins in serum exosomes. No significant increases in rectal temperature were observed immediately after exposure, which the authors interpret as mainly nonthermal effects.

Outcomes measured

Spatial learning and memory (cognitive function)
EEG disturbance
Hippocampal (DG area) structural/synaptic changes
Hippocampal protein expression changes (e.g., Snapin, charged multivesicular body protein 3)
Serum exosome protein expression changes (multiple proteins)
Rectal/core temperature change (thermal vs nonthermal effects)

Limitations

Sample size not reported in provided abstract/excerpts
Exposure metric (e.g., SAR/power density) not reported in provided abstract/excerpts
Animal study; generalizability to humans not established in provided abstract/excerpts
Details of randomization/blinding and behavioral/EEG assessment methods not provided in provided abstract/excerpts

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "microwave",
    "source": null,
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "6 min/day, 5 days/week, 6 weeks (long-term exposure); frequencies 2.856 and 9.375 GHz"
  },
  "population": "Mice",
  "sample_size": null,
  "outcomes": [
    "Spatial learning and memory (cognitive function)",
    "EEG disturbance",
    "Hippocampal (DG area) structural/synaptic changes",
    "Hippocampal protein expression changes (e.g., Snapin, charged multivesicular body protein 3)",
    "Serum exosome protein expression changes (multiple proteins)",
    "Rectal/core temperature change (thermal vs nonthermal effects)"
  ],
  "main_findings": "After long-term exposure to 2.856 and 9.375 GHz microwaves, spatial reference learning and memory and DG-area structure were reported as impaired, with EEG disturbance and hippocampal structural damage. The study reports decreased hippocampal Snapin and increased charged multivesicular body protein 3, and frequency-specific decreases in several proteins in serum exosomes. No significant increases in rectal temperature were observed immediately after exposure, which the authors interpret as mainly nonthermal effects.",
  "effect_direction": "harm",
  "limitations": [
    "Sample size not reported in provided abstract/excerpts",
    "Exposure metric (e.g., SAR/power density) not reported in provided abstract/excerpts",
    "Animal study; generalizability to humans not established in provided abstract/excerpts",
    "Details of randomization/blinding and behavioral/EEG assessment methods not provided in provided abstract/excerpts"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "microwave",
    "2.856 GHz",
    "9.375 GHz",
    "long-term exposure",
    "mice",
    "spatial learning",
    "memory",
    "hippocampus",
    "dentate gyrus",
    "synaptic vesicles",
    "Snapin",
    "CHMP3",
    "serum exosomes",
    "proteomics",
    "EEG",
    "nonthermal effects",
    "ICNIRP 2020"
  ],
  "suggested_hubs": [
    {
      "slug": "who-icnirp",
      "weight": 0.6,
      "reason": "Excerpts state exposure duration was based on ICNIRP 2020 guidelines."
    }
  ]
}

AI can be wrong. Always verify against the paper.

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: 10.1186/s12964-022-01011-1
PubMed: Not supplied

Read the original paper →

Related papers

← Back to the Research Library