Dose-dependent impact of extremely low-frequency electromagnetic field (ELF-EMF) on the neuroplasticity in the hippocampus of adult rats.

PAPER pubmed Neuroscience letters 2026 Animal study Effect: mixed Evidence: Low

Read original paper → DOI: 10.1016/j.neulet.2026.138520 PMID: 41544927 Evidence Lab

Abstract

Extremely low-frequency electromagnetic field (ELF-EMF) therapy is gaining attention for its potential benefits in treating neurodegenerative conditions. However, the underlying molecular mechanisms responsible for the possible protective effects of ELF-EMF remain unclear. Our previous research revealed that ELF-EMF exposure can establish a new "set-point" for stress responses, with outcomes dependent on field intensity. Stress hormones have been shown to modulate hippocampal function and plasticity. Therefore, our study aimed to assess how ELF-EMF exposure affects the expression of transcripts related to hippocampal plasticity, including genes related to neurogenesis (BDNF, TrkB, GAP43), synaptic activity (PSD95, SYN1), and cell survival (Bcl-2, Bcl-xL, Bak1). Adult rats were exposed to ELF-EMF (50 Hz) at 1 mT and 7 mT intensities for three 7-day periods, 1 h/day, with 3-week break between each cycle. A subset of animals was sacrificed after each exposure to collect hippocampi. The relative expression of neural/synaptic genes and anti-/pro-survival factors was measured by real-time quantitative polymerase chain reaction. Our findings indicate that ELF-EMF exposure modulates mRNA expression of neural/synaptic genes and anti-/pro-survival factors. The direction and dynamics of changes depend on ELF-EMF intensity and the number of exposures. "Low-intensity" ELF-EMF (1 mT) increased pro-neuroplastic factors expression, while "high-intensity" ELF-EMF (7 mT) decreased them. In summary, "low-intensity" ELF-EMF enhances adaptive processes like neuroplasticity by eliciting a mild stress response, while "high-intensity" exposure disrupts homeostasis and brain function by inducing severe stress. Our findings indicate that the overall effects of ELF-EMF depend on the intricate interplay between stress reactions and long-term brain plasticity.

AI evidence extraction

At a glance

Study type

Animal study

Effect direction

mixed

Population

Adult rats

Sample size

—

Exposure

ELF therapy · Three 7-day periods, 1 h/day, with 3-week break between each cycle

Evidence strength

Low

Confidence: 78% · Peer-reviewed: yes

Main findings

Adult rats exposed to 50 Hz ELF-EMF showed modulation of hippocampal mRNA expression for neural/synaptic and survival-related genes, with effects depending on field intensity and number of exposure cycles. Low-intensity exposure (1 mT) increased pro-neuroplastic factor expression, while high-intensity exposure (7 mT) decreased them.

Outcomes measured

Hippocampal mRNA expression of neurogenesis-related genes (BDNF, TrkB, GAP43)
Hippocampal mRNA expression of synaptic activity genes (PSD95, SYN1)
Hippocampal mRNA expression of cell survival/apoptosis-related genes (Bcl-2, Bcl-xL, Bak1)

Limitations

Sample size not reported in provided abstract/metadata
Outcomes limited to transcript (mRNA) expression; functional/behavioral outcomes not described in provided abstract
Mechanistic interpretation framed around stress response but direct stress hormone measurements are not described in provided abstract

View raw extracted JSON

{
    "study_type": "animal",
    "exposure": {
        "band": "ELF",
        "source": "therapy",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": "Three 7-day periods, 1 h/day, with 3-week break between each cycle"
    },
    "population": "Adult rats",
    "sample_size": null,
    "outcomes": [
        "Hippocampal mRNA expression of neurogenesis-related genes (BDNF, TrkB, GAP43)",
        "Hippocampal mRNA expression of synaptic activity genes (PSD95, SYN1)",
        "Hippocampal mRNA expression of cell survival/apoptosis-related genes (Bcl-2, Bcl-xL, Bak1)"
    ],
    "main_findings": "Adult rats exposed to 50 Hz ELF-EMF showed modulation of hippocampal mRNA expression for neural/synaptic and survival-related genes, with effects depending on field intensity and number of exposure cycles. Low-intensity exposure (1 mT) increased pro-neuroplastic factor expression, while high-intensity exposure (7 mT) decreased them.",
    "effect_direction": "mixed",
    "limitations": [
        "Sample size not reported in provided abstract/metadata",
        "Outcomes limited to transcript (mRNA) expression; functional/behavioral outcomes not described in provided abstract",
        "Mechanistic interpretation framed around stress response but direct stress hormone measurements are not described in provided abstract"
    ],
    "evidence_strength": "low",
    "confidence": 0.7800000000000000266453525910037569701671600341796875,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "ELF-EMF",
        "50 Hz",
        "hippocampus",
        "neuroplasticity",
        "gene expression",
        "BDNF",
        "TrkB",
        "GAP43",
        "PSD95",
        "SYN1",
        "Bcl-2",
        "Bcl-xL",
        "Bak1",
        "stress response",
        "rats",
        "dose-dependent"
    ],
    "suggested_hubs": []
}

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AI-extracted fields are generated from the abstract/metadata and may be incomplete or incorrect. This content is for informational purposes only and is not medical advice.

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