Possible effects of RF EMR on contextual fear conditioning, hippocampal perivascular space, apoptosis and adrenal gland microarchitecture in rats

Behavioural Brain Research · 2025 · Harm · Low evidence

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HarmLow evidencePaper 2676

Study snapshot

PublicationBehavioural Brain Research · 2025

Study typeanimal

Reported directionHarm

Evidence ratingLow

Abstract

Category: Neuroscience Tags: RF-EMR, hippocampus, adrenal gland, apoptosis, contextual fear conditioning, perivascular space, mobile phone radiation DOI: 10.1016/j.bbr.2025.115424 URL: sciencedirect.com Overview As mobile phone technology rapidly expands worldwide, concerns over the possible health effects induced by radiofrequency electromagnetic radiation (RF-EMR) have intensified. This study investigates the hypothesis that chronic 900 MHz RF-EMR exposure could dysregulate the stress response system (specifically the HPA axis) via non-thermal mechanisms. The study explores potential alterations in the microarchitecture of the adrenal gland and vulnerability in brain regions such as the hippocampus, which may lead to altered behaviors in rats. Methods - Male albino Wistar rats (aged four weeks, 50-60g) were exposed to 900 MHz radiation from a mobile phone for one hour daily over four weeks. - On day 29, control, sham exposed, and RF-EMR exposed rats underwent contextual fear conditioning tests. - After behavioral testing, rats were euthanized for examination of hippocampal and adrenal gland cytoarchitecture. Findings - RF-EMR exposed rats demonstrated significantly elevated transitions between bright and dark compartments in the avoidance box, and decreased latency to enter the dark compartment. - Marked apoptosis was observed in the CA3 region, and the perivascular space in the hippocampus was significantly enlarged in the exposed group. - The zona fasciculata of the adrenal gland displayed apoptotic-like changes, lymphocytic infiltrates, and congested sinusoids in the RF-EMR exposed group. - The cytoarchitecture of the adrenal medulla remained comparable across all groups. Conclusion Chronic exposure to RF-EMR at 900 MHz resulted in: - Changes in contextual fear conditioning behavior. - Enlargement of hippocampal perivascular space and induction of apoptosis in the CA3 region. - Apoptotic and inflammatory changes in the zona fasciculata of the adrenal gland. These findings indicate a clear association between chronic RF-EMR exposure and adverse neurobehavioral as well as histological changes, reinforcing the link between electromagnetic fields and health risks.

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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 albino Wistar rats (aged four weeks, 50–60 g)

Sample sizeNot supplied

ExposureRF · 900 MHz · 1 hour daily for 4 weeks

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Rats exposed to 900 MHz RF-EMR from a mobile phone for 1 hour/day for 4 weeks showed altered avoidance behavior (increased transitions between compartments and decreased latency to enter the dark compartment). Histology showed marked apoptosis in hippocampal CA3 and significantly enlarged hippocampal perivascular space, along with apoptotic-like and inflammatory changes in the adrenal zona fasciculata; adrenal medulla cytoarchitecture was comparable across groups.

Outcomes measured

Contextual fear conditioning behavior
Avoidance box transitions between bright/dark compartments
Latency to enter dark compartment
Hippocampal CA3 apoptosis
Hippocampal perivascular space size
Adrenal gland microarchitecture (zona fasciculata, adrenal medulla)
Adrenal zona fasciculata apoptotic-like changes
Adrenal zona fasciculata lymphocytic infiltrates
Adrenal zona fasciculata congested sinusoids

Limitations

Sample size not reported in the abstract
Specific exposure metrics (e.g., SAR, power density) not reported in the abstract
Details of randomization/blinding not reported in the abstract

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": 900,
    "sar_wkg": null,
    "duration": "1 hour daily for 4 weeks"
  },
  "population": "Male albino Wistar rats (aged four weeks, 50–60 g)",
  "sample_size": null,
  "outcomes": [
    "Contextual fear conditioning behavior",
    "Avoidance box transitions between bright/dark compartments",
    "Latency to enter dark compartment",
    "Hippocampal CA3 apoptosis",
    "Hippocampal perivascular space size",
    "Adrenal gland microarchitecture (zona fasciculata, adrenal medulla)",
    "Adrenal zona fasciculata apoptotic-like changes",
    "Adrenal zona fasciculata lymphocytic infiltrates",
    "Adrenal zona fasciculata congested sinusoids"
  ],
  "main_findings": "Rats exposed to 900 MHz RF-EMR from a mobile phone for 1 hour/day for 4 weeks showed altered avoidance behavior (increased transitions between compartments and decreased latency to enter the dark compartment). Histology showed marked apoptosis in hippocampal CA3 and significantly enlarged hippocampal perivascular space, along with apoptotic-like and inflammatory changes in the adrenal zona fasciculata; adrenal medulla cytoarchitecture was comparable across groups.",
  "effect_direction": "harm",
  "limitations": [
    "Sample size not reported in the abstract",
    "Specific exposure metrics (e.g., SAR, power density) not reported in the abstract",
    "Details of randomization/blinding not reported in the abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "RF-EMR",
    "radiofrequency electromagnetic radiation",
    "900 MHz",
    "mobile phone radiation",
    "hippocampus",
    "CA3",
    "apoptosis",
    "perivascular space",
    "contextual fear conditioning",
    "HPA axis",
    "adrenal gland",
    "zona fasciculata",
    "Wistar rats"
  ],
  "suggested_hubs": [
    {
      "slug": "mobile-phones",
      "weight": 0.9,
      "reason": "Exposure described as 900 MHz radiation from a mobile phone."
    }
  ]
}

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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: 10.1016/j.bbr.2025.115424
PubMed: Not supplied

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