A study of neurotoxic biomarkers, c-fos and GFAP after acute exposure to GSM radiation at 900 MHz in the picrotoxin model of rat brains.

Neurotoxicology · 2011 · Mixed · Low evidence

← Research stream

MixedLow evidencePaper 4464

Study snapshot

PublicationNeurotoxicology · 2011

Study typeanimal

Reported directionMixed

Evidence ratingLow

Abstract

The acute effects of microwave exposure from the Global System for Mobile Communication (GSM) were studied in rats, using 900MHz radiation at an intensity similar to mobile phone emissions. Acute subconvulsive doses of picrotoxin were then administered to the rats and an experimental model of seizure-proneness was created from the data. Seventy-two adult male Sprague-Dawley rats underwent immunochemical testing of relevant anatomical areas to measure induction of the c-fos neuronal marker after 90min and 24h, and of the glial fibrillary acidic protein (GFAP) 72h after acute exposure to a 900MHz electromagnetic field (EMF). The experimental set-up facilitated measurement of absorbed power, from which the average specific absorption rate was calculated using the finite-difference time-domain (FDTD) 2h after exposure to EMF radiation at 1.45W/kg in picrotoxin-treated rats and 1.38W/kg in untreated rats. Ninety minutes after radiation high levels of c-fos expression were recorded in the neocortex and paleocortex along with low hippocampus activation in picrotoxin treated animals. Most brain areas, except the limbic cortical region, showed important increases in neuronal activation 24h after picrotoxin and radiation. Three days after picrotoxin treatment, radiation effects were still apparent in the neocortex, dentate gyrus and CA3, but a significant decrease in activity was noted in the piriform and entorhinal cortex. During this time, glial reactivity increased with every seizure in irradiated, picrotoxin-treated brain regions. Our results reveal that c-fos and glial markers were triggered by the combined stress of non-thermal irradiation and the toxic effect of picrotoxin on cerebral tissues.

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 typeanimal

Effect directionmixed

PopulationAdult male Sprague-Dawley rats (including picrotoxin-treated and untreated groups)

Sample size72

ExposureRF · 900 MHz · 1.45 W/kg · acute exposure (c-fos measured at 90 min and 24 h; GFAP at 72 h)

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

After acute 900 MHz exposure at an intensity similar to mobile phone emissions, irradiated picrotoxin-treated rats showed high c-fos expression in neocortex and paleocortex at 90 min with low hippocampal activation. At 24 h, most brain areas (except limbic cortical region) showed increased neuronal activation after picrotoxin and radiation; at 72 h, radiation effects were still apparent in neocortex, dentate gyrus and CA3, with decreased activity in piriform and entorhinal cortex, and glial reactivity increased with every seizure in irradiated, picrotoxin-treated regions.

Outcomes measured

c-fos expression (neuronal activation marker)
GFAP (glial fibrillary acidic protein; glial reactivity)
brain-region-specific neuronal activation in seizure-proneness (picrotoxin model)

Limitations

Animal study (rat model), not directly generalizable to humans
Effects described in the context of combined stressors (radiation plus picrotoxin), limiting attribution to RF exposure alone
Acute exposure only; no chronic exposure assessment

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": 900,
    "sar_wkg": 1.45,
    "duration": "acute exposure (c-fos measured at 90 min and 24 h; GFAP at 72 h)"
  },
  "population": "Adult male Sprague-Dawley rats (including picrotoxin-treated and untreated groups)",
  "sample_size": 72,
  "outcomes": [
    "c-fos expression (neuronal activation marker)",
    "GFAP (glial fibrillary acidic protein; glial reactivity)",
    "brain-region-specific neuronal activation in seizure-proneness (picrotoxin model)"
  ],
  "main_findings": "After acute 900 MHz exposure at an intensity similar to mobile phone emissions, irradiated picrotoxin-treated rats showed high c-fos expression in neocortex and paleocortex at 90 min with low hippocampal activation. At 24 h, most brain areas (except limbic cortical region) showed increased neuronal activation after picrotoxin and radiation; at 72 h, radiation effects were still apparent in neocortex, dentate gyrus and CA3, with decreased activity in piriform and entorhinal cortex, and glial reactivity increased with every seizure in irradiated, picrotoxin-treated regions.",
  "effect_direction": "mixed",
  "limitations": [
    "Animal study (rat model), not directly generalizable to humans",
    "Effects described in the context of combined stressors (radiation plus picrotoxin), limiting attribution to RF exposure alone",
    "Acute exposure only; no chronic exposure assessment"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "GSM",
    "900 MHz",
    "RF-EMF",
    "microwave exposure",
    "specific absorption rate",
    "SAR",
    "c-fos",
    "GFAP",
    "glial reactivity",
    "picrotoxin",
    "seizure-proneness",
    "Sprague-Dawley rats",
    "FDTD"
  ],
  "suggested_hubs": [
    {
      "slug": "mobile-phones",
      "weight": 0.9,
      "reason": "GSM 900 MHz exposure described as similar to mobile phone emissions."
    },
    {
      "slug": "animal-studies",
      "weight": 0.85,
      "reason": "Experimental rat study measuring brain biomarkers after RF exposure."
    }
  ]
}

AI can be wrong. Always verify against the paper.

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.neuro.2011.04.003
PubMed: 21524663

Read the original paper →

Related papers

← Back to the Research Library