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

Abstract

BackgroundExtremely 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 Ca2+. 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.MethodsExperiments 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.ResultsThe 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).ConclusionsThe 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.

Increased aggression and reduced aversive learning in honey bees exposed to extremely low frequency electromagnetic fields

“…Furthermore, the honey bee alarm pheromone has been shown to increase levels of the biogenic amines serotonin and dopamine, with increases in these amine levels being associated with increased likelihood of a bee to sting [41]. Some studies investigating the effects of EMF on invertebrates have suggested that increased biogenic amine levels lead to increases in behavioural activity [42, 43]. While no studies have yet analysed changes in dopamine levels following ELF EMF exposure, these previous studies suggest that biogenic amine levels may be a potential area to investigate to elucidate the underlying mechanisms of ELF EMF induced changes in insect behaviour.…”

Open Questions on the Electromagnetic Field Contribution to the Risk of Neurodegenerative Diseases

“…EMF treatment should be conducted under well-controlled conditions, supported by evidence of biological activity for EMF, which may lead to a positive or negative outcome depending on the exposure parameters. This is to ensure the safety of therapeutic treatments involving EMF, even more so when a direct action of an EMF occurring at one body location may have an indirect effect in another location [ 13 , 14 , 15 , 16 ]. According to published results, the most beneficial therapeutic cycle should include 10 to 14 daily treatments.…”

The impact of chronic exposure to a magnetic field on energy metabolism and locomotion of Blaptica dubia

“…Numerous findings have indicated that an MF can modulate various aspects of insect physiology and behavior (Stanojević et al 2005;Starick et al 2005;Rauš et al 2009;Savić et al 2011;Yang et al 2011;Todorović et al 2012;Todorović et al 2013;Dimitrijević et al 2014;Jankowska et al 2015;Pavlović et al 2016;Wyszkowska et al 2016;Sheppard et al 2017;Xu et al 2017;Zmejkoski et al 2017;Maliszewska et al 2018;Todorović et al 2019).…”