Exposure to 50 Hz electromagnetic field changes the efficiency of the scorpion alpha toxin.

The journal of venomous animals and toxins including tropical diseases · 2015 · Mixed · Low evidence

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MixedLow evidencePaper 4740

Exposure to 50 Hz ELF-EMF at 0.7 mT modified the effects of LqhαIT on cockroach nervous system activity: toxin effects decreased on cercal nerve activity but increased on connective nerve activity. In biotests, toxicity of LqhαIT on cockroaches was reduced by…

Study snapshot

PublicationThe journal of venomous animals and toxins including tropical diseases · 2015

Study typeanimal

Reported directionMixed

Evidence ratingLow

Abstract

BACKGROUND: Extremely low-frequency (50 Hz) electromagnetic field (ELF-EMF) is produced by electric power transmission lines and electronic devices of everyday use. Some phenomena are proposed as "first effects" of ELF-EMF: the discrete changes in the membrane potential and the increase of the calcium channel activity as well as the intracellular concentration of Ca(2+). Interaction of the scorpion alpha toxin with the sodium channel depends on the orientation of the charges and may be perturbed by changes in the membrane polarization. The toxin induces overexcitability in the nervous system and an increase in the neurotransmitters released with different consequences, mainly the paralysis of muscles. We assumed that the exposure to ELF-EMF 0.7 mT will change the effects of the insect selective scorpion alpha toxin (recombinant LqhαIT from Leiurus quinquestriatus hebraeus) at the level of the cercal nerve function, the synaptic transmission and on the level of entire insect organism. Taking into account the compensatory mechanisms in organisms, we tested in addition ten times higher ELF-EMF on whole insects. METHODS: Experiments were performed in vivo on cockroaches (Periplaneta americana) and in vitro - on isolated cockroach abdominal nerve cord with cerci. In biotests, the effects of LqhαIT (10(-8) M) were estimated on the basis of the insect ability to turn back from dorsal to ventral side. Three groups were compared: the control one and the two exposed to ELF-EMF - 0.7 and 7 mT. Bioelectrical activity of the cercal nerve and of the connective nerve that leaves the terminal abdominal ganglion was recorded using extracellular electrodes. LqhαIT (5 × 10(-8) M) induced modifications of neuronal activity that were observed in the control cockroach preparations and in the ones exposed to ELF-EMF (0.7 mT). The exposure to ELF-EMF was carried out using coils with a size appropriate to the examined objects. RESULTS: The exposure to ELF-EMF (0.7 mT) modified the effects of LqhαIT (5 × 10(-8) M) on activity of the cercal nerve and of the connective nerve. We observed a decrease of the toxin effect on the cercal nerve activity, but the toxic effect of LqhαIT on the connective nerve was increased. Biotests showed that toxicity of LqhαIT (10(-8) M) on cockroaches was reduced by the exposure to ELF-EMF (0.7 and 7 mT). CONCLUSIONS: The exposure to 50 Hz ELF-EMF modified the mode of action of the anti-insect scorpion alpha toxin LqhαIT at cellular level of the cockroach nervous system and in biotests. Toxin appeared as a usefull tool in distinguishing between the primary and the secondary effects of ELF-EMF.

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

PopulationCockroaches (Periplaneta americana); isolated cockroach abdominal nerve cord with cerci (in vitro preparation)

Sample sizeNot supplied

ExposureELF · 5e-05 MHz

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Outcomes measured

Cercal nerve bioelectrical activity (extracellular recordings)
Connective nerve bioelectrical activity (extracellular recordings)
Toxicity/functional impairment in biotest (ability to turn back from dorsal to ventral side)
Modification of scorpion alpha toxin (recombinant LqhαIT) effects on nervous system activity

Limitations

Sample size not reported in abstract
Exposure duration/timing not reported in abstract
Animal/insect model; relevance to human health not addressed in abstract
Outcomes focus on interaction with a specific toxin rather than standalone EMF effects

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": null,
    "frequency_mhz": 5e-05,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Cockroaches (Periplaneta americana); isolated cockroach abdominal nerve cord with cerci (in vitro preparation)",
  "sample_size": null,
  "outcomes": [
    "Cercal nerve bioelectrical activity (extracellular recordings)",
    "Connective nerve bioelectrical activity (extracellular recordings)",
    "Toxicity/functional impairment in biotest (ability to turn back from dorsal to ventral side)",
    "Modification of scorpion alpha toxin (recombinant LqhαIT) effects on nervous system activity"
  ],
  "main_findings": "Exposure to 50 Hz ELF-EMF at 0.7 mT modified the effects of LqhαIT on cockroach nervous system activity: toxin effects decreased on cercal nerve activity but increased on connective nerve activity. In biotests, toxicity of LqhαIT on cockroaches was reduced by ELF-EMF exposure at both 0.7 and 7 mT.",
  "effect_direction": "mixed",
  "limitations": [
    "Sample size not reported in abstract",
    "Exposure duration/timing not reported in abstract",
    "Animal/insect model; relevance to human health not addressed in abstract",
    "Outcomes focus on interaction with a specific toxin rather than standalone EMF effects"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "ELF-EMF",
    "50 Hz",
    "0.7 mT",
    "7 mT",
    "scorpion alpha toxin",
    "LqhαIT",
    "Leiurus quinquestriatus hebraeus",
    "cockroach",
    "Periplaneta americana",
    "cercal nerve",
    "synaptic transmission",
    "extracellular recording",
    "toxicity biotest"
  ],
  "suggested_hubs": []
}

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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: 10.1186/s40409-015-0040-9
PubMed: 26430395

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