RF Safe

In vitro exposure of neuronal networks to the 5G-3.5 GHz signal

2023 · Mixed · Low evidence

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MixedLow evidencePaper 395

At SAR near guidelines (1 and 3 W/kg), the authors report no conclusive evidence that 3.5 GHz RF exposure impacts neuronal activity in vitro. At high SAR (28 W/kg), both continuous-wave and 5G-modulated signals decreased bursting and total firing rates during…

Study snapshot

Publicationmanual · 2023
Study typein_vitro
Reported directionMixed
Evidence ratingLow

Abstract

In vitro exposure of neuronal networks to the 5G-3.5 GHz signal Canovi A, Orlacchio R, Poulletier de Gannes F, et al. In vitro exposure of neuronal networks to the 5G-3.5 GHz signal. Front Public Health. 2023;11:1231360. Published 2023 Aug 7. doi:10.3389/fpubh.2023.1231360 Abstract Introduction: The current deployment of the fifth generation (5G) of wireless communications raises new questions about the potential health effects of exposure to radiofrequency (RF) fields. So far, most of the established biological effects of RF have been known to be caused by heating. We previously reported inhibition of the spontaneous electrical activity of neuronal networks in vitro when exposed to 1.8 GHz signals at specific absorption rates (SAR) well above the guidelines. The present study aimed to assess the effects of RF fields at 3.5 GHz, one of the frequencies related to 5G, on neuronal activity in-vitro. Potential differences in the effects elicited by continuous-wave (CW) and 5G-modulated signals were also investigated. Methods: Spontaneous activity of neuronal cultures from embryonic cortices was recorded using 60-electrode multi-electrode arrays (MEAs) between 17 and 27 days in vitro. The neuronal cultures were subjected to 15 min RF exposures at SAR of 1, 3, and 28 W/kg. Results: At SAR close to the guidelines (1 and 3 W/kg), we found no conclusive evidence that 3.5 GHz RF exposure impacts the activity of neurons in vitro. On the contrary, CW and 5G-modulated signals elicited a clear decrease in bursting and total firing rates during RF exposure at high SAR levels (28 W/kg). Our experimental findings extend our previous results, showing that RF, at 1.8 to 3.5 GHz, inhibits the electrical activity of neurons in vitro at levels above environmental standards. Excerpts Dissociated primary cortical neurons were isolated from the cortex of embryonic (E18–E19) Sprague–Dawley rats (Janvier-Labs, Saint-Berthevin, France) as described in Moretti et al. (7).... The RF generation unit was located outside the incubator (Figure 1A) and consisted of (i) an RF signal generator (SMBV100A, Rohde & Schwarz) used to generate either CW or 5G-modulated signal at 3.5 GHz, ... The 3.5 GHz 5G signal used corresponds to 5G NR (release 15, Digital Standards SMBVB-K444, Rohde & Schwarz) with FDD duplexing, QPSK modulation and 100 MHz channel bandwidth. The signal was led to the TEM cell through a 1.5 m coaxial precision test cable (CBL-1.5 m-SMNM+, Mini-circuits, United States; 1.2 dB insertion loss at 3.5 GHz) and SMA connectors.... In conclusion, we have given here experimental evidence that RF exposure of cultured cortical neurons at 3.5 GHz CW or 5G-modulated signals at 28 W/kg induces a decrease in total firing and bursting activities. The threshold for such inhibitory effect exceeds the maximal SAR recommended by ICNIRP for human exposure (1). Considering the studies mentioned above, we may hypothesize that the rate of the temperature rise plays an important role in eliciting specific cellular responses. Further studies are needed to elucidate the role of temperature rate and thus investigate the mechanism underlying these observations. Open access paper: frontiersin.org

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 typein_vitro
Effect directionmixed
PopulationDissociated primary cortical neurons from embryonic (E18–E19) Sprague–Dawley rats; neuronal cultures recorded 17–27 days in vitro
Sample sizeNot supplied
ExposureRF · 3500 MHz · 15 min
Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

At SAR near guidelines (1 and 3 W/kg), the authors report no conclusive evidence that 3.5 GHz RF exposure impacts neuronal activity in vitro. At high SAR (28 W/kg), both continuous-wave and 5G-modulated signals decreased bursting and total firing rates during exposure.

Outcomes measured

  • Spontaneous electrical activity of neuronal networks (multi-electrode arrays)
  • Bursting rate
  • Total firing rate

Limitations

  • In vitro model (cultured embryonic rat cortical neurons), not direct evidence in humans
  • Short exposure duration (15 min)
  • Effects observed at high SAR (28 W/kg) above guideline levels; limited relevance to typical environmental exposures
  • Sample size not stated in provided abstract/metadata
View raw extracted JSON
{
  "study_type": "in_vitro",
  "exposure": {
    "band": "RF",
    "source": "5G signal (3.5 GHz) in TEM cell; CW and 5G-modulated",
    "frequency_mhz": 3500,
    "sar_wkg": null,
    "duration": "15 min"
  },
  "population": "Dissociated primary cortical neurons from embryonic (E18–E19) Sprague–Dawley rats; neuronal cultures recorded 17–27 days in vitro",
  "sample_size": null,
  "outcomes": [
    "Spontaneous electrical activity of neuronal networks (multi-electrode arrays)",
    "Bursting rate",
    "Total firing rate"
  ],
  "main_findings": "At SAR near guidelines (1 and 3 W/kg), the authors report no conclusive evidence that 3.5 GHz RF exposure impacts neuronal activity in vitro. At high SAR (28 W/kg), both continuous-wave and 5G-modulated signals decreased bursting and total firing rates during exposure.",
  "effect_direction": "mixed",
  "limitations": [
    "In vitro model (cultured embryonic rat cortical neurons), not direct evidence in humans",
    "Short exposure duration (15 min)",
    "Effects observed at high SAR (28 W/kg) above guideline levels; limited relevance to typical environmental exposures",
    "Sample size not stated in provided abstract/metadata"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "in vitro",
    "neuronal networks",
    "multi-electrode array",
    "3.5 GHz",
    "5G NR",
    "radiofrequency",
    "continuous wave",
    "modulated signal",
    "SAR",
    "bursting",
    "firing rate",
    "ICNIRP"
  ],
  "suggested_hubs": [
    {
      "slug": "5g-policy",
      "weight": 0.72,
      "reason": "Study explicitly evaluates a 3.5 GHz 5G-modulated signal (5G NR) and compares with CW."
    },
    {
      "slug": "who-icnirp",
      "weight": 0.55,
      "reason": "Findings discussed relative to ICNIRP maximal SAR recommendations."
    }
  ]
}
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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: 10.3389/fpubh.2023.1231360
PubMed: Not supplied

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