Exposure to 1800 MHz LTE electromagnetic fields under proinflammatory conditions decreases the response strength and increases the acoustic threshold of auditory cortical neurons

Abstract

Exposure to 1800 MHz LTE electromagnetic fields under proinflammatory conditions decreases the response strength and increases the acoustic threshold of auditory cortical neurons Samira Souffi, Julie Lameth, Quentin Gaucher, Délia Arnaud-Cormos, Philippe Lévêque, Jean-Marc Edeline, Michel Mallat. Exposure to 1800 MHz LTE electromagnetic fields under proinflammatory conditions decreases the response strength and increases the acoustic threshold of auditory cortical neurons. Sci Rep. 2022 Mar 8;12(1):4063. doi: 10.1038/s41598-022-07923-9. Abstract Increased needs for mobile phone communications have raised successive generations (G) of wireless technologies, which could differentially affect biological systems. To test this, we exposed rats to single head- only exposure of a 4G long-term evolution (LTE)-1800 MHz electromagnetic field (EMF) for 2 h. We then assessed the impact on microglial space coverage and electrophysiological neuronal activity in the primary auditory cortex (ACx), under acute neuroinflammation induced by lipopolysaccharide. The mean specific absorption rate in the ACx was 0.5 W/kg. Multiunit recording revealed that LTE-EMF triggered reduction in the response strength to pure tones and to natural vocalizations, together with an increase in acoustic threshold in the low and medium frequencies. Iba1 immunohistochemistry showed no change in the area covered by microglia cell bodies and processes. In healthy rats, the same LTE-exposure induced no change in response strength and acoustic threshold. Our data indicate that acute neuroinflammation sensitizes neuronal responses to LTE-EMF, which leads to an altered processing of acoustic stimuli in the ACx. Excerpt In conclusion, our study reveals that a single head-only exposure to LTE-1800 MHz can interfere with the neuronal responses of cortical neurons to sensory stimuli. In line with previous characterizations of the effect of GSM-signal, our results show that the impact of LTE signal on neuronal activity varies according to the health state. Acute neuroinflammation sensitize neuronal responses to LTE-1800 MHz, resulting in altered cortical processing of auditory stimuli. Open access paper: nature.com

AI evidence extraction

Main findings

After a single 2 h head-only 1800 MHz LTE exposure (mean SAR in ACx 0.5 W/kg), rats with acute LPS-induced neuroinflammation showed reduced auditory cortical response strength to pure tones and natural vocalizations and increased acoustic threshold at low and medium frequencies. No change was observed in microglial area coverage. In healthy rats, the same LTE exposure produced no change in response strength or acoustic threshold.

Outcomes measured

• Auditory cortex (ACx) neuronal electrophysiological activity (multiunit response strength to pure tones and natural vocalizations)
• Acoustic threshold (low and medium frequencies)
• Microglial space coverage in ACx (Iba1 immunohistochemistry; area covered by microglia cell bodies and processes)

Limitations

• Sample size not reported in provided text
• Only acute, single 2 h exposure assessed
• Findings depend on health state (LPS-induced acute neuroinflammation vs healthy)
• Microglial outcome limited to Iba1 area coverage measure (no other inflammatory markers described)

Suggested hubs

• 5g-policy (0.15)
  Study concerns cellular network RF exposure (LTE/4G), potentially relevant to broader wireless generation discussions but not directly 5G.

{
    "study_type": "animal",
    "exposure": {
        "band": "RF",
        "source": "LTE (4G) head-only exposure",
        "frequency_mhz": 1800,
        "sar_wkg": 0.5,
        "duration": "2 h"
    },
    "population": "Rats (including acute neuroinflammation induced by lipopolysaccharide; also healthy rats)",
    "sample_size": null,
    "outcomes": [
        "Auditory cortex (ACx) neuronal electrophysiological activity (multiunit response strength to pure tones and natural vocalizations)",
        "Acoustic threshold (low and medium frequencies)",
        "Microglial space coverage in ACx (Iba1 immunohistochemistry; area covered by microglia cell bodies and processes)"
    ],
    "main_findings": "After a single 2 h head-only 1800 MHz LTE exposure (mean SAR in ACx 0.5 W/kg), rats with acute LPS-induced neuroinflammation showed reduced auditory cortical response strength to pure tones and natural vocalizations and increased acoustic threshold at low and medium frequencies. No change was observed in microglial area coverage. In healthy rats, the same LTE exposure produced no change in response strength or acoustic threshold.",
    "effect_direction": "mixed",
    "limitations": [
        "Sample size not reported in provided text",
        "Only acute, single 2 h exposure assessed",
        "Findings depend on health state (LPS-induced acute neuroinflammation vs healthy)",
        "Microglial outcome limited to Iba1 area coverage measure (no other inflammatory markers described)"
    ],
    "evidence_strength": "low",
    "confidence": 0.7800000000000000266453525910037569701671600341796875,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "1800 MHz",
        "LTE",
        "4G",
        "RF-EMF",
        "specific absorption rate",
        "SAR 0.5 W/kg",
        "auditory cortex",
        "electrophysiology",
        "multiunit recording",
        "acoustic threshold",
        "neuroinflammation",
        "lipopolysaccharide",
        "microglia",
        "Iba1"
    ],
    "suggested_hubs": [
        {
            "slug": "5g-policy",
            "weight": 0.1499999999999999944488848768742172978818416595458984375,
            "reason": "Study concerns cellular network RF exposure (LTE/4G), potentially relevant to broader wireless generation discussions but not directly 5G."
        }
    ]
}

Comments

Log in to comment.

No comments yet.