Acute effects of 2.856 GHz and 1.5 GHz microwaves on spatial memory abilities and CREB-related pathways

Scientific reports · 2021 · Harm · Low evidence

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HarmLow evidencePaper 1122

Study snapshot

PublicationScientific reports · 2021

Study typeanimal

Reported directionHarm

Evidence ratingLow

Abstract

Acute effects of 2.856 GHz and 1.5 GHz microwaves on spatial memory abilities and CREB-related pathways Shengzhi Tan, Hui Wang, Xinping Xu, Li Zhao, Jing Zhang, Ji Dong, Binwei Yao, Haoyu Wang, Yanhui Hao, Hongmei Zhou, Yabing Gao, Ruiyun Peng. Acute effects of 2.856 GHz and 1.5 GHz microwaves on spatial memory abilities and CREB-related pathways. Sci Rep. 2021 Jun 11;11(1):12348. doi: 10.1038/s41598-021-91622-4. Abstract This study aimed to evaluate the acute effects of 2.856 GHz and 1.5 GHz microwaves on spatial memory and cAMP response element binding (CREB)-related pathways. A total of 120 male Wistar rats were divided into four groups: a control group (C); 2.856 GHz microwave exposure group (S group); 1.5 GHz microwave exposure group (L group); and 2.856 and 1.5 GHz cumulative exposure group (SL group). Decreases in spatial memory abilities, changes in EEG, structural injuries, and the downregulation of phosphorylated-Ak strain transforming (p-AKT), phosphorylated-calcium/calmodulin-dependent protein kinase II (p-CaMKII), phosphorylated extracellular signal regulated kinase (p-ERK) and p-CREB was observed 6 h after microwave exposure. Significant differences in the expression of p-CaMKII were found between the S and L groups. The power amplitudes of the EEG waves (θ, δ), levels of structural injuries and the expression of p-AKT, p-CaMK II, p-CREB, and p-ERK1/2 were significantly different in the S and L groups compared to the SL group. Interaction effects between the 2.856 and 1.5 GHz microwaves were found in the EEG and p-CREB changes. Our findings indicated that 2.856 GHz and 1.5 GHz microwave exposure induced a decline in spatial memory, which might be related to p-AKT, p-CaMK II, p-CREB and p-ERK1/2. pubmed.ncbi.nlm.nih.gov The power density in all three RF conditions was 10 milliwatts per square centimeter. Excerpt In terms of the molecular level, differences in the expression of p-CaMKII/CaMKII between 2.856 GHz and 1.5 GHz were found, which suggests the different sensitivities of the signal pathways to microwaves with different frequencies. Interaction effects of the two microwave frequencies were found for the changes in p- CREB/CREB. The accumulative exposure of the 2.856 GHz and 1.5 GHz microwaves aggravated the downregulation of p-CREB/CREB. Previous studies used combined exposure to communication microwaves (849 MHz and 1.95 GHz), but none of these studies analyzed the interaction effects53,54,55,56. The present study provides new insights into the biological effects of microwave radiation. Microwaves affect multiple metabolic pathways, and the frequency played an important role in the biological effects. The results related to frequency-dependent effects suggested that microwave safety standards should be based on the frequency. Past safety standards were primarily based on radiation power, and radiation frequency was defined only in a rough range57. The interaction effects suggested that the biological effects caused by electromagnetic waves were much more complicated than previously thought. More attention should be given to this field.

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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 directionharm

PopulationMale Wistar rats

Sample size120

Exposuremicrowave · acute; outcomes assessed 6 h after exposure

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

In 120 male Wistar rats, acute microwave exposure at 2.856 GHz, 1.5 GHz, or cumulative exposure to both (power density 10 mW/cm^2 in all RF conditions) was associated with decreased spatial memory abilities, EEG changes, structural injuries, and downregulation of p-AKT, p-CaMKII, p-ERK1/2, and p-CREB observed 6 h after exposure. Differences between frequency groups were reported (e.g., p-CaMKII differed between 2.856 GHz and 1.5 GHz), and cumulative exposure differed from single-frequency exposure for several measures; interaction effects between the two frequencies were noted for EEG and p-CREB changes.

Outcomes measured

Spatial memory abilities
EEG changes (θ, δ power amplitudes)
Structural injuries
p-AKT expression
p-CaMKII expression
p-ERK1/2 expression
p-CREB expression
p-CaMKII/CaMKII ratio
p-CREB/CREB ratio

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "microwave",
    "source": null,
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "acute; outcomes assessed 6 h after exposure"
  },
  "population": "Male Wistar rats",
  "sample_size": 120,
  "outcomes": [
    "Spatial memory abilities",
    "EEG changes (θ, δ power amplitudes)",
    "Structural injuries",
    "p-AKT expression",
    "p-CaMKII expression",
    "p-ERK1/2 expression",
    "p-CREB expression",
    "p-CaMKII/CaMKII ratio",
    "p-CREB/CREB ratio"
  ],
  "main_findings": "In 120 male Wistar rats, acute microwave exposure at 2.856 GHz, 1.5 GHz, or cumulative exposure to both (power density 10 mW/cm^2 in all RF conditions) was associated with decreased spatial memory abilities, EEG changes, structural injuries, and downregulation of p-AKT, p-CaMKII, p-ERK1/2, and p-CREB observed 6 h after exposure. Differences between frequency groups were reported (e.g., p-CaMKII differed between 2.856 GHz and 1.5 GHz), and cumulative exposure differed from single-frequency exposure for several measures; interaction effects between the two frequencies were noted for EEG and p-CREB changes.",
  "effect_direction": "harm",
  "limitations": [],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "microwave",
    "radiofrequency",
    "2.856 GHz",
    "1.5 GHz",
    "Wistar rats",
    "spatial memory",
    "EEG",
    "CREB",
    "p-CREB",
    "AKT",
    "CaMKII",
    "ERK",
    "power density 10 mW/cm^2",
    "acute exposure",
    "frequency-dependent effects",
    "cumulative exposure",
    "interaction effects"
  ],
  "suggested_hubs": [
    {
      "slug": "who-icnirp",
      "weight": 0.22,
      "reason": "Abstract/excerpt discusses implications for microwave safety standards and frequency-dependent effects."
    }
  ]
}

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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: 10.1038/s41598-021-91622-4
PubMed: 34117282

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