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Parasitol Res
Parasitol Res
Parasitology Research
0932-0113
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Springer Berlin Heidelberg Berlin/Heidelberg

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8326
10.1007/s00436-024-08326-7
Research
Anthropogenic electromagnetic radiation alters the transcription levels of the genes encoding the SIFamide and myoinhibitory peptide and their receptors in Ixodes ricinus synganglion
http://orcid.org/0009-0006-9096-7929
Šofranková Lívia 1
http://orcid.org/0009-0007-0326-2582
Baňas Miroslav 1
http://orcid.org/0000-0002-6284-6517
Pipová Natália 1
http://orcid.org/0000-0002-5613-9226
Majláth Igor 1
http://orcid.org/0000-0002-8162-3415
Kurimský Juraj 2
http://orcid.org/0000-0002-0902-8400
Cimbala Roman 2
http://orcid.org/0000-0003-4383-3996
Zbojovský Ján 2
http://orcid.org/0000-0002-4472-1016
Šimo Ladislav 3
http://orcid.org/0000-0002-8571-4947
Majláthová Viktória viktoria.majlathova@upjs.sk

1
1 grid.11175.33 0000 0004 0576 0391 Department of Animal Physiology, Pavol Jozef Šafárik University in Košice, Šrobárova 2, 04180 Košice, Slovakia
2 https://ror.org/05xm08015 grid.6903.c 0000 0001 2235 0982 Department of Electric Power Engineering, Faculty of Electrical Engeneering and Informatics, Technical University of Košice, Mäsiarska 74, 04120 Košice, Slovakia
3 https://ror.org/04k031t90 grid.428547.8 0000 0001 2169 3027 Laboratoire de Santé Animale, Unitè Mixte de Recherche de Biologie Molèculaire et d’Immunologie Parasitaires (UMR BIPAR), École Nationale Vétérinaire d’Alfort, INRAE, F-94700 Maisons-Alfort, ANSES France
Section Editor: Van Lun Low.

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© The Author(s) 2024
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https://creativecommons.org/licenses/by/4.0/ Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
The research of the influences of man-made electromagnetic fields on tick physiology has been very sparse and long neglected since the pioneer studies published in 1996 and 2000. Once multiple behavioral tests confirmed an attraction and possible perception of electromagnetic fields in ticks, a new interest in this topic erupted in recent years. In this study, qRT-PCR is utilized to determine the changes in the mRNA transcript levels of neuropeptides SIFamide and myoinhibitory peptide (mip and sifa) and their representative receptors (mip-r1 and sifa-r1) in the synganglia of the tick Ixodes ricinus irradiated by 900 MHz radiofrequency electromagnetic field. It was determined that 40 V/m intensity has a significant suppressory effect on the transcript levels of all genes after at least 60 minutes of constant exposure in both sexes. Commonly occurring intensity of radiation in urban areas (2 V/m) produced an elevation in mRNA levels after various timespans in every gene. A significant decrease of transcript abundances was detected in females after one hour of exposure to 2 V/m. Results of this study widen the knowledge of EMF-induced alterations in the neurophysiology of I. ricinus, the most commonly distributed hard tick in Europe.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00436-024-08326-7.

Keywords

Ticks
Electromagnetic radiation
Synganglion
Neuropeptide levels
http://dx.doi.org/10.13039/501100005357 Agentúra na Podporu Výskumu a Vývoja APVV-17-0372 APVV-17-0372 APVV-17-0372 APVV-17-0372 APVV-17-0372 APVV-17-0372 APVV-17-0372 APVV-17-0372 Šofranková Lívia Baňas Miroslav Pipová Natália Majláth Igor Kurimský Juraj Cimbala Roman Zbojovský Ján Majláthová Viktória Internal Scientific Grant System of the Pavol Jozef Šafárik University in KošiceVVGS-2022-2192 VVGS-2022-2192 Šofranková Lívia Baňas Miroslav http://dx.doi.org/10.13039/501100001665 Agence Nationale de la Recherche ANR-21-CE14-0012 ANR-10-LABX-62-IBEID ANR-21-CE14-0012 Šofranková Lívia Pipová Natália Šimo Ladislav COSTCA21170 CA21170 CA21170 CA21170 CA21170 Šofranková Lívia Baňas Miroslav Pipová Natália Majláth Igor Majláthová Viktória Pavol Jozef Šafárik University in KošiceOpen access funding provided by The Ministry of Education, Science, Research and Sport of the Slovak Republic in cooperation with Centre for Scientific and Technical Information of the Slovak Republic

issue-copyright-statement© Springer-Verlag GmbH Germany, part of Springer Nature 2024
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pmcIntroduction

The omnipresence of anthropogenic non-ionizing electromagnetic radiation and its effects on biosphere has been a polarizing topic in the last 30 years, with several research studies describing its diverse impacts on living organisms. Many publications report on negative effects of electromagnetic field (EMFs) presence (Zielinski et al. 2020; Molina-Montenegro et al. 2023), while some studies show no impact (Port et al. 2003; Vijver et al. 2014), and other conclude on the possibility of positive effects on certain biological processes (Parivar et al. 2006; Saliev et al. 2014). However, reports on the negative influences prevail. The most studied negative effects of non-ionizing EMFs are the increased presence of reactive oxygen species and DNA damage (Phillips et al. 2009; Calcabrini et al. 2017), carcinogenesis (Lerchl et al. 2015), changes in the gene expression (Zhao et al. 2007), and ion imbalance on the cell membrane (Panagopoulos et al. 2015; Wust et al. 2020).

In arthropod research, it has been confirmed that anthropogenic EMFs can have adverse effects on the physiology and behavior. Negative effects on the reproductive fitness and development, the fitness of the offspring, and various influences on the body dimensions were reported in crustaceans, fruit flies, and honeybees (Panagopoulos 2012; Harsanyi et al. 2022; Li et al. 2022). Several publications conclude that exposure to radiation leads to increased stress response, not only confirmed by behavioral trials, but also presenting in the upregulation of the stress and immune response-related genes and in the elevation of the levels of stress-related metabolites (Newland et al. 2015; Wyszkowska et al. 2016; Valadez-Lira et al. 2017). Exposure also had an adverse impact on the flying pattern (Shepherd et al. 2021; Migdal et al. 2023), biorhythms (Bartos et al. 2019), and the orientation and navigation of both migratory and non-migratory arthropods (Perez et al. 1999; Cammaerts et al. 2013; Balmori 2015). In addition, a possible neurodegenerative effect of anthropogenic EMF was determined, manifesting in the disruption of the learning process and memory in fruit flies, bees, and ants (Cammaerts et al. 2012; El Kholy and El Husseiny 2013; Shepherd et al. 2018).

Ticks showed a certain attraction to radiofrequency (RF) radiation in numerous studies, where it is hypothesized, that there might be a positive relationship between ticks and enhanced electromagnetic field presence in the habitat (Vargová et al. 2017, 2018; Frątczak et al. 2020; Baňas et al. 2023). These interpretations suggest that the presence of electromagnetic fields could influence tick distribution, especially in connection with strongly urbanized spaces with high levels of electromagnetic pollution. More interestingly, the study of Frątczak et al. (2020) reports that Rickettsia-infected ticks prefer irradiated area of the labyrinth more than uninfected ticks. Despite all of the interesting observations in behavioral studies, research of EMF effects on tick physiology has been neglected. Our recent pioneer investigation showed a significant alteration of the expression levels of four randomly selected neuropeptide genes in the central nervous system of Ixodes ricinus after exposure to anthropogenic 900-MHz radiation (Šofranková et al. 2023).

Since the very first neuropeptide - periviscerokinin was identified in the tick synganglion (Neupert et al. 2005), an extensive network of tick neuropeptidergic neurons has been mapped. Subsequently, two neuropeptides, myoinhibitory peptide (MIP) and SIFamide (SIFa) and their receptors (MIP_R1, SIFa_R1), were extensively studied (Šimo et al. 2009b, 2013; Vancová et al. 2019). Among numerous distinct anti-MIP and anti-SIFa immunoreactive neurons in the synganglion, prominent cells coexpressing both these neuropeptides were found in innervation of salivary glands and hindgut of Ixodes scapularis (Šimo et al. 2009b; Šimo and Park 2014) suggesting a multifunctional role of these neuropeptides in tick biology. In addition, various MIP-R1 or SIFa-R1 immunoreactive neurons were identified across I. scapularis synganglion (Šimo et al. 2013) implying the MIP and SIFamide signalling within the neural circuit. Because the same study already showed dynamics in mip, sifa, sifa-r1, and mip-r1 transcript levels during the Ixodes feeding, here we were interested how 900-MHz electromagnetic radiation influences these transcripts in the major vector of Lyme disease in Europe, the tick I. ricinus.

Methods

Ticks and irradiation protocol

We followed the previously established protocol of tick irradiation described in Šofranková et al. (2023). Questing adult ticks I. ricinus were collected by the flagging method in a meadow near the village Dubovica, Slovakia. Current data about the nearby EMF sources and overall EMF intensity are: town Lipany (cellphone tower by a signal provider O2 Slovakia 1–10 kW to a 1.3-km distance) (https://elektrosmog-info.voxo.eu/mapa-vysielacov accessed on 12/1/2024), town Sabinov up to 2 V/m (13 km from the site of collection) (Ochrana obyvateľstva SR pred účinkami elektromagnetických polí (vuje.sk) accessed on 12/1/2024). Female and male ticks were kept separately in the plastic 50-ml tubes with mesh lids in the laboratory desiccator until the experiment.

A total of total 360 I. ricinus ticks were used in this study, 180 females and 180 males in total. Ticks were divided into three biological replications, 120 ticks per each replication. Ticks in each biological replication were split into 24 groups according to sex, radiation applied, and length of exposure to radiation (Table 1). Each experimental group contained five individuals, which were put into a 2-ml plastic tube with dampened filter paper to ensure proper humidity for the ticks. Table 1 Distribution of ticks into the experimental groups in the presented experiment

Sex	Radiation	Exposure time	No. of individuals	
Females	900 MHz, 2 V/m	10 minutes	3 × 5 ticks	
60 minutes	3 × 5 ticks	
3 hours	3 × 5 ticks	
24 hours	3 × 5 ticks	
900 MHz, 40 V/m	10 minutes	3 × 5 ticks	
60 minutes	3 × 5 ticks	
3 hours	3 × 5 ticks	
24 hours	3 × 5 ticks	
No radiation	10 minutes	3 × 5 ticks	
60 minutes	3 × 5 ticks	
3 hours	3 × 5 ticks	
24 hours	3 × 5 ticks	
Males	900 MHz, 2 V/m	10 minutes	3 × 5 ticks	
60 minutes	3 × 5 ticks	
3 hours	3 × 5 ticks	
24 hours	3 × 5 ticks	
900 MHz, 40 V/m	10 minutes	3 × 5 ticks	
60 minutes	3 × 5 ticks	
3 hours	3 × 5 ticks	
24 hours	3 × 5 ticks	
No radiation	10 minutes	3 × 5 ticks	
60 minutes	3 × 5 ticks	
3 hours	3 × 5 ticks	
24 hours	3 × 5 ticks	

Ticks were irradiated by a constant, polarized EMF with the frequency of 900 MHz, produced by N5183A Agilent Technologies (Kuala Lumpur, MY) generator. The Amplifier Research Model 50W1000B (AR RF/Microwave Instrumentation, USA) was used to generate the intensity of 40 V/m. The source of the EMF was connected to the Double-Ridged Waveguide Horn Antenna HF907 (Rohde and Schwarz, Munich, DE). Ticks were irradiated in the anechoic chamber (1710–100 model, Comtest Engineering, Leyde, NL), tubes containing ticks were placed 2 m from the antenna and elevated to 1 m height (Supplementary Fig. 1).

The electromagnetic field generated in the chamber was unmodified, two distinctive intensities were generated for this experiment: 2 V/m and 40 V/m. Lower EMF intensity was selected to represent the frequently occurring intensity in urbanized habitats. This intensity was measured in villages with close proximity to town Košice, Slovakia and reported on in the conference paper by Zbojovský et al. (2022). Intensity 40 V/m is the maximal intensity of EMF allowed to use in Slovakia according to the Act No. 537/2007 (Ministry of Health of Slovak Republic 2007). Ticks were irradiated for four separate time spans: for 10 minutes, 60 minutes, 3 hours, or 24 hours. Control groups were placed into the anechoic chamber for the same time-length as irradiated groups, but without the radiation generator on.

Synganglia dissection and qRT-PCR

We followed the previously established protocol of dissection as described in Šofranková et al. (2023). Briefly, tick synganglia were dissected immediately after the irradiation according to the protocol and immediately frozen in tubes on dry ice. Total RNA was extracted from frozen tissues by RNeasy Micro kit (Qiagen, Venlo, NL) and transcribed to cDNA as synthetized by the RevertAid H Minus First Strand cDNA Synthesis kit (ThermoScientific, Waltham, MA USA) using oligoDT primers. Four genes tested in this study were: two neuropeptide genes — mip (Genbank: GQ214555) and sifa (GenBank: GO214556) and two neuropeptide receptor genes — mip-r1 (GenBank: AAF46037) and sifa-r1 (GenBank: AAN13859) (Šimo et al. 2013). A ribosomal subunit S4 protein gene (rps4) (GeneBank: DQ066214) was used as a reference gene for normalization of data (Koči et al. 2013).

qRT-PCR, utilizing LightCycler 480 II thermocycler (Roche, Meylan, FR), was used to determine the levels of transcripts. All experiments were performed in three biological and two technical replicates in 96-well opaque plates. A 20-µl reaction was prepared containing 10 µl of LightCycler® 480 SYBR® Green I Master mastermix (Roche), 1 µl of 10 mM forward and 1 µl of 10 mM reverse primer (Supplementary Table 1), 7 µl of PCR-grade water, and 1 µl of template cDNA. The cycling protocol consisted of the preincubation step for 5 minutes at 95 °C and 45 cycles of amplification for 10 seconds at 95 °C, 10 seconds of annealing at the temperature listed in the Supplementary Table 1, and 10 seconds of 72 °C. The melting curve was examined from 65 to 97 °C and the PCR products were sequenced to verify the amplification of targeted genes (Eurofins, Luxembourg, LU).

The fold difference was assessed by the 2−∆∆CT ratio calculation (Livak and Schmittgen 2001). Statistical significance of the results was determined by two-tailed Student’s t-test in the GraphPad Prism 5 (GraphPad Software Inc., San Diego, CA, USA).

Results

Levels of transcript for sifa were elevated in ticks exposed to 2 V/m, specifically in females in the 24-hour experiment to 4.45-folds (Fig. 1A) and in males in the 10-minute exposure time group to 1.88-folds (Fig. 1B). Significantly decreased levels of mRNA for sifa were determined in females regardless of the radiation intensity for 60 minutes (0.14-folds for 2 V/m intensity, p < 0.001; 0.03-folds for 40 V/m, p < 0.001). A significant decrease was also noted in ticks exposed to the higher intensity for 3 hours to 0.15-folds in females (p < 0.01) and to 0.09-folds in males (p < 0.001). In males exposed to 40 V/m intensity for 24 hours, mRNA levels decreased to 0.26-folds (p < 0.05). Lower amount of transcript was also determined in the group of males irradiated only 10 minutes (0.45) and for 1 hour (0.41-folds) by 40 V/m.Fig. 1 The fold difference of transcript levels in I. ricinus synganglia after irradiation. A Levels of sifa in females; B levels of sifa in males; C levels of sifa-r1 in females; D levels of sifa-r1 in males. The ribosomal protein S4 (rps4) was used for normalization of the data shown in the figure; the level of mRNA of control (non-irradiated) ticks was assigned to be 1. The graphs show means and standard errors of mean, the asterisks show a significant fold difference when compared to the control group. The Student’s t-test was utilized to calculate the statistical significance, the indicated p values are *p < 0.05; **p < 0.01; ***p < 0.001

The results for the fold change in mRNA levels of sifa-r1 were similar to sifa transcript levels. An elevation in mRNA abundance was found in the groups irradiated by the lower intensity (2 V/m), specifically 2.11-fold in females after 3 hours of radiation exposure, and after 24 hours to 9.51-folds (Fig. 1C). In males, non-significant elevation was determined after 10-minute exposure (fold change 2.22) and after 60 minutes of exposure (2.43-fold) to the lower intensity (Fig. 1D). A significant decrease in the mRNA levels in female groups were found after the exposure to 60 minutes to 2 V/m radiation (0.17-folds, p < 0.001). Similarly, a decrease was determined in the groups irradiated for 1 hour (to 0.09-folds, p < 0.001) and 3 hours (to 0.30-folds, p < 0.01) by 40 V/m radiation. In the male groups, the amount of sifa-r1 transcripts was significantly lowered (fold change 0.08, p < 0.001) in the experimental groups irradiated for 10 minutes when utilizing 40 V/m. Another decrease was determined in males exposed to radiation for 3 hours (0.36-folds for 2 V/m intensity, p < 0.01; 0.009-folds for 40 V/m, p < 0.001) or 24 hours (0.13-folds for 2 V/m intensity, p < 0.001; 0.04-folds for 40 V/m, p < 0.001) regardless of the radiation intensity.

Transcript levels of mip were elevated in females irradiated by the lower intensity radiation for 3 hours (16.3 folds) and 24 hours (42.2-folds), and after the 24-hour irradiation when utilizing the intensity 40 V/m (21.1-folds) (Fig. 2A). A significant decrease of mRNA levels was detected in the female groups after 1 hour (0.01-folds, p < 0.001) and 3 hours (0.06-folds, p < 0.001) of 40 V/m irradiation. In males, a significant decrease in transcript levels for this gene was after 3 hours (0.23-folds, p < 0.05; 0.03-folds, p < 0.001) and 24 hours (0.03-folds, p < 0.001; 0.13-folds, p < 0.01) of irradiation, regardless of the intensity (Fig. 2B). After 10-minute exposure, an elevation in transcript amount to 14.5-folds was found for male groups in the 2 V/m experiment and a decrease in the same transcript to 0.58-folds in the 40 V/m experiment, while in female groups no change in the levels of mip transcript was determined after 10 minutes of exposure.Fig. 2 Fold differences of mRNA levels in irradiated I. ricinus synganglia. A Levels of mip in females; B levels of mip in males; C levels of mip-r1 in females; D levels of mip-r1 in males. The ribosomal protein S4 (rps4) was used for normalization of the data shown in the figure; the level of mRNA of control (non-irradiated) ticks was assigned to be 1. The graphs show means and standard errors of mean, the asterisks showing a significant fold difference when compared to the control group. The Student’s t-test was utilized to calculate the statistical significance, the indicated p values are *p < 0.05; **p < 0.01; ***p < 0.001

For mip-r1 an increase in transcript levels was found in both sexes irradiated for 10 minutes with the intensity 2 V/m (2.8-folds for females and 5.9-folds for males) (Fig. 2 C, D). Another increase was determined in the female groups exposed to the same intensity for 3 hours (2.3-folds) or 24 hours (17.6-folds). A significant decrease in transcript levels of mip-r1 to 0.67-folds (p < 0.05) was noted in females irradiated with the lower intensity (2 V/m) for the duration of 60 minutes and in females exposed to the higher intensity (40 V/m). The mRNA levels were decreased after 1-hour exposure to 0.02-folds (p < 0.001) and to 0.11-folds (p < 0.01) after 3 hours. In males, the mRNA levels in the group irradiated for 3 h by 40 V/m were decreased significantly to 0.04-folds (p < 0.001). Similar to the levels of mip, the transcript levels of mip-r1 were significantly decreased in the male groups irradiated for 24 hours with either intensity (0.02-folds for group exposed to 2 V/m, p < 0.001; 0.14-folds for the 40 V/m group, p < 0.01).

Discussion

Studies regarding relationships between ticks and anthropogenic electromagnetic fields are not numerous, however behavioral tests proved that a certain attraction of ticks to the area of enhanced EMF exists (Vargová et al. 2018, 2022; Baňas et al. 2023). This poses not only a question if the EMF affects ticks positively, negatively, or has no effect at all, but also of the mechanism of perception of EMFs in ticks. EMF perception out of the range of visible light could aid in the habitat orientation, as has been proven in several species of invertebrates (Boles and Lohmann 2003; Dommer et al. 2008; Vácha et al. 2008). Perceptive sensilla for infrared radiation, similar to the heat pits of rattlesnakes has been already identified in the Haller’s organ of ticks by Mitchell et al. 2017. In earlier studies about tick reactions to EMFs it was implied that the EMF perception in ticks can provide a useful information about the location of the host (Vargová et al. 2017). This has been corroborated recently by a study of England et al. 2023, where ticks were passively attracted to the host by static electric fields created between the host and the questing tick. Even if the actual transfer of tick to the host is a passive physical process, sensing the minute changes in the EMFs caused by approaching host would be an advantageous adaptation for a tick.

Even though most published studies on alterations in gene expression by EMFs focus on genes connected to the immune and stress responses and to the cell cycle regulation (Liu et al. 2015; Wang et al. 2022), EMFs can affect the gene expression for signaling molecules as well. A single study describing the effects on the transcript levels in the tick synganglion was published last year (Šofranková et al. 2023). An alteration of the expression of neuropeptides in tick synganglia exposed to EMF could be connected to the behavior observed in the behavioral tests. Neuropeptidergic neurons in tick synganglion were previously relatively well described (Šimo et al. 2009a). Several peripheral functions of neuropeptides have been found; however, more attention was given to the innervation of osmoregulatory organs, like salivary glands and the hindgut (Šimo et al. 2009b; Šimo and Park 2014). In terms of the study of sensory nervous system, location and functions of sensillae and sensory pits, especially those in the Haller’s organ, are also relatively known (Hummel et al. 2007; Leonovich 2020). However, the neural connections leading from sensory organs to CNS are more obscured. Moreover, a very limited amount of knowledge about the interconnectivity between neurons inside the synganglion is available. Projections of neurons within the synganglion create a complex axonal network of processing centers, although which exact information are these centers processing and the communication between them requires an extensive study (El Shoura 1989; Szlendak and Oliver 1992). The location of olfactory centers and optical centers receiving information from the Haller’s organ and the eyes is now determined (Hummel et al. 2007; Šimo et al. 2009a; Menezes et al. 2021), but these centers might process other stimuli as well. Identification of infrared-sensitive sensilla in the Haller’s organ (Mitchell et al. 2017) could be pointing to a fact that perhaps olfactory lobes deserve a closer attention in the future, when researching in the topic EMF-sensing in ticks.

Here, the transcripts for all the investigated genes are reported to be present in the synganglion of the unfed ticks as well as during the entire course of Ixodes female feeding (Šimo et al. 2013). In our experiment, we do notice that the amounts of mRNA in irradiated ticks were suppressed especially when the 40 V/m intensity was used. With the lower intensity (2 V/m) irradiation levels of transcripts fluctuated within the 3 hours from the start of exposure. However, it is difficult to postulate at this point if the omnipresent or intentional anthropogenic irradiation of either intensity could have an overarching effect on the state of readiness of ticks for host search, host attachment or disrupt the feeding process. More extensive tests involving more experimental animals should be conducted to prove this effect.

Results of this study clearly point to the fact that the neuropeptide transcript levels in the tick I. ricinus can be altered by artificial 900-MHz frequency especially when the higher intensity was utilized. The attraction of both sexes of this species to the EMFs was confirmed in previous studies, where ticks preferred the irradiated part of the modified T-labyrinth after 24 hours of irradiation (Baňas et al. 2023; Frątczak et al. 2020). The frequency of 900 MHz used in this study represents a typical anthropogenic electromagnetic radiation, as it is a frequency widely used for the cell phone signal. The lower intensity (2 V/m) is one of the most commonly occurring intensity of EMF in the urbanized areas (Zbojovský et al. 2022), while the higher intensity of 40 V/m represents the highest intensity allowed for the cell phone signal providers in Slovakia (Ministry of Health of Slovak Republic 2007).

While we report on a strong suppression of mRNA levels for neuropeptides in the synganglion for the groups exposed to 40 V/m radiation in this, as well as in the previous study (Šofranková et al. 2023), it cannot be concluded that this elevated intensity is harming ticks. As mentioned above, in the behavioral test that utilized the same frequency and intensity of EMF for 24 hours, ticks significantly preferred the exposed part of the labyrinth and were not repelled by radiation (Baňas et al. 2023). Results of this study regarding the transcript levels in the synganglia of females after 24 hours of constant irradiation show no change from the controls, while they were significantly suppressed in males. This could indicate that a certain type of habituation or adaptation to this type of stimulus could be occurring, as is reported on in Vargová et al. (2017).

The contrast between the reaction of the female and male groups is very interesting. Males seemed to be more affected by radiation, as we obtained more significant changes in experimental groups of males than in female groups. On the other hand, in our previously published study, where different genes were analyzed, we found higher responsiveness in females (Šofranková et al. 2023), despite the conditions of the experiment being the same as in this study. Interestingly, no significant sex difference in the responsiveness of I. ricinus to irradiation was found (Baňas et al. 2023). These discrepancies in EMF effects could possibly result from the penetration properties of electromagnetic field. The difference in morphology and body size (Herssens et al. 2022) between the sexes could be one of the factors we need to consider, since females possess a smaller scutum, which could alter the effects of the radiation on the synganglion beneath. As the specific absorption rates (SAR) of the tick cuticule and scutum have not been studies; yet, it cannot be estimated, if this is the cause of the differences (Panagopoulos et al. 2013).

In male groups exposed to 40 V/m, the suppression of transcript levels starts after 10 minutes, then the levels normalize and later the transcript levels lower again after 3 hours. This effect could suggest a presence of some unknown molecular compensatory mechanisms. No changes or only slightly lowered levels found in both sexes of ticks irradiated for only 10 minutes could be explained by a compensatory mechanism as well.

Lower (2 V/m) intensity showed various effect in female groups; however, less of the statistically significant results were obtained. An upregulation of mRNA levels of studied genes in the first 10 to 60 minutes in males is noted. In the previous study, the transcript levels of neuropeptides kinin and FGLa-related allatostatin were also slightly higher than controls (Šofranková et al. 2023). A short-term exposure in 3-minute intervals to the 900-MHz radiation of the 700 µW/m2 power density (approx. 0.5 V/m) has produced a specific jerking movement in questing Dermacentor reticulatus as reported by Vargová et al. (2017).

Significantly lower amounts of transcripts in the female synganglion were found in three genes (mip-r1, sifa-r1, and sifa) after 1 hour of exposure. Interestingly, the results of the open field test with 900 MHz and 0.6 V/m of radiation, the females of I. ricinus started walking significantly longer distances in the irradiated part of the set-up approximately after 60 to 100 minutes of constant irradiation. Movement dynamics of ticks walking in the irradiated part of the arena was affected as well (Vargová et al. 2022). Non-significant upregulation of almost all of the studied genes was noted in females irradiated for 3 hours and more, which again might point to an adaptation to the stimulus, or an overcompensation in the reparatory mechanisms after a sudden suppression in the mRNA levels (Kokot et al. 2009). Frątczak et al. (2020) and Vargová et al. (2022) report no significant result in EMF preference of females after 24 hours of irradiation with 900 MHz, 0.6 V/m of irradiation. However, we did find a suppression of the transcript levels in three neuropeptide genes in the synganglion in our previous study (Šofranková et al. 2023). A significant decrease in mRNA levels was observed in males after 3 and 24 hours of constant exposure. This result contrasts with the study in the modified T-labyrinth, where irradiating I. ricinus males by 0.6 V/mresulted in a higher percentage of ticks preferring the exposed arm of the labyrinth (Frątczak et al. 2020).

Results of this study confirm the previously published findings, that man-made frequencies of EMF do significantly alter the neuropeptide transcript levels in the synganglion of one of the most common tick species in Europe. Topic of electromagnetic influences is a relatively new research interest within the field of acarology and a more extensive research is necessary to fully uncover and comprehend the mechanisms behind these responses. Future research should entail full body and organ transcriptomic analyses of irradiated ticks, the study of possible physiological changes during the course of feeding post irradiation, utilizing both artificial feeding system and laboratory animals and during metamorphosis and reproduction.

Tick attraction to EMF and changes in the expression of signaling molecules also poses a question of the tick distribution in urbanized areas, as mentioned in several previous studies (Vargová et al. 2018; Frątczak et al. 2020; Šofranková et al. 2023). Increase in the incidence of human-tick encounters is likely multifactorial — a combination of high density of potential hosts, plenty of suitable microhabitats, loss of natural habitat due to rapid urbanization, or climate change (Medlock et al. 2013; Heylen et al. 2019). With the limited information available to us so far, it is hard to tell if and how strongly would the presence of man-made electromagnetic fields impact the distribution of ticks within city spaces. However, the omnipresence of electromagnetic pollution should not be omitted when evaluating possible factors contributing to elevated tick presence in urban habitats.

Conclusions

In conclusion, levels of neuropeptide transcripts in the synganglion investigated in presented study are significantly suppressed by a short-term high intensity cell phone frequency irradiation. Exposure to a frequency more commonly present in the urban environment produced insignificant, although interesting altering effects on the mRNA of studied genes. As several previous studies regarding this topic suggested, presence of electromagnetic fields should not be disregarded as one of the possible abiotic factors contributing to the shift in tick distribution towards urbanized microhabitats. However, to fully understand the basis of the attraction of ticks to the heightened electromagnetic radiation and its possible influences on tick biology and subsequently on their distribution, a more extensive and comprehensive study of the molecular aspects of tick nervous and sensory systems under experimental irradiation needs to be conducted in the future.

Supplementary Information

Below is the link to the electronic supplementary material.Supplementary file1. Supplementary Figure 1: Schematic visualization of anechoic chamber set-up used in this study. N5183A Agilent Technologies (Kuala Lumpur, MY) generator was used to produce desired electromagnetic field, and Amplifier Research Model 50W1000B (AR RF/Microwave Instrumentation, USA) to generate 40 V/m radiation. The distance from the Double-Ridged Waveguide Horn Antenna HF907 (Rohde and Schwarz, Munich, DE) (∆) and the target of irradiation – tube with ticks (*) was 2 meters. Target of irradiation was elevated to the height of 1 meter. Experiment was conducted in total darkness. The temperature was constant 21 °C and relative humidity in the chamber was 60 %. Each tube with ticks contained a moistened strip of filter paper to ensure high levels of humidity. Supplementary Table 1: A list of qRT-PCR primers and the aligning temperatures used in the study (DOCX 104 KB)

Author contribution

Conceptualization: V.M., I.M.and L.Ši.; Methodology: L.Šo., J.K. and J.Z.; Validation: L.Ši. and V.M.; Investigation: L.Šo., M.B., N.P. and J.Z.; Resources: V.M., I.M., L.Ši. and R.C.; Formal Analysis and Data Curation: L.Šo.; Writing—Original Draft Preparation: L.Šo.; Writing—Review and Editing: V.M. and L.Ši.; Visualization: L.Šo.; Supervision: V.M., I.M. and L.Ši.; Funding Acquisition: V.M., I.M., L.Ši. and J.K.

Funding

Open access funding provided by The Ministry of Education, Science, Research and Sport of the Slovak Republic in cooperation with Centre for Scientific and Technical Information of the Slovak Republic. This research was supported by the Slovak Research and Development Agency (grant numbers: APVV-17–0372, APVV-19–0440); Internal Scientific Grant System of the Pavol Jozef Šafárik University in Košice (grant number: VVGS-2022–2192); Nadácia Tatra banky foundation: scholarships for doctoral students 2023; French National Research Agency (ANR) (grant number: ANR-21-CE14-0012), project AxoTick to L. Šimo. UMR BIPAR is supported by the French Government’s Investissement d’Avenir program, Laboratoire d’Excellence “Integrative Biology of Emerging Infectious Diseases” (grant number: ANR-10-LABX-62-IBEID); and the COST Action CA21170 “Prevention, anticipation and mitigation of tick-borne disease risk applying the DAMA protocol (PRAGMATICK)”.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval

Not applicable.

Competing interests

The authors declare no competing interests.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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References

Balmori A Anthropogenic radiofrequency electromagnetic fields as an emerging threat to wildlife orientation Sci Total Environ 2015 518–519 58 60 10.1016/j.scitotenv.2015.02.077 25747364
Balmori A (2015) Anthropogenic radiofrequency electromagnetic fields as an emerging threat to wildlife orientation. Sci Total Environ 518–519:58–60. 10.1016/j.scitotenv.2015.02.07725747364 10.1016/j.scitotenv.2015.02.077
Baňas M Šofranková L Kurimský J Interspecific differences in the behavioral response of ticks exposed to radiofrequency electromagnetic radiation Exp Appl Acarol 2023 91 477 485 10.1007/s10493-023-00847-7 37819593
Baňas M, Šofranková L, Kurimský J et al (2023) Interspecific differences in the behavioral response of ticks exposed to radiofrequency electromagnetic radiation. Exp Appl Acarol 91:477–485. 10.1007/s10493-023-00847-737819593 10.1007/s10493-023-00847-7
Bartos P Netusil R Slaby P Weak radiofrequency fields affect the insect circadian clock J R Soc Interface 2019 16 20190285 10.1098/rsif.2019.0285 31530135
Bartos P, Netusil R, Slaby P et al (2019) Weak radiofrequency fields affect the insect circadian clock. J R Soc Interface 16:20190285. 10.1098/rsif.2019.028531530135 10.1098/rsif.2019.0285
Boles LC Lohmann KJ True navigation and magnetic maps in spiny lobsters Nature 2003 421 60 63 10.1038/nature01226 12511953
Boles LC, Lohmann KJ (2003) True navigation and magnetic maps in spiny lobsters. Nature 421:60–63. 10.1038/nature0122612511953 10.1038/nature01226
Calcabrini C Mancini U De Bellis R Effect of extremely low-frequency electromagnetic fields on antioxidant activity in the human keratinocyte cell line NCTC 2544 Biotech and App Biochem 2017 64 415 422 10.1002/bab.1495
Calcabrini C, Mancini U, De Bellis R et al (2017) Effect of extremely low-frequency electromagnetic fields on antioxidant activity in the human keratinocyte cell line NCTC 2544. Biotech and App Biochem 64:415–422. 10.1002/bab.149510.1002/bab.1495
Cammaerts M-C De Doncker P Patris X GSM 900 MHz radiation inhibits ants’ association between food sites and encountered cues Electromagn Biol Med 2012 31 151 165 10.3109/15368378.2011.624661 22268919
Cammaerts M-C, De Doncker P, Patris X et al (2012) GSM 900 MHz radiation inhibits ants’ association between food sites and encountered cues. Electromagn Biol Med 31:151–165. 10.3109/15368378.2011.62466122268919 10.3109/15368378.2011.624661
Cammaerts M-C Rachidi Z Bellens F De Doncker P Food collection and response to pheromones in an ant species exposed to electromagnetic radiation Electromagn Biol Med 2013 32 315 332 10.3109/15368378.2012.712877 23320633
Cammaerts M-C, Rachidi Z, Bellens F, De Doncker P (2013) Food collection and response to pheromones in an ant species exposed to electromagnetic radiation. Electromagn Biol Med 32:315–332. 10.3109/15368378.2012.71287723320633 10.3109/15368378.2012.712877
Dommer DH Gazzolo PJ Painter MS Phillips JB Magnetic compass orientation by larval Drosophila melanogaster J Insect Physiol 2008 54 719 726 10.1016/j.jinsphys.2008.02.001 18359039
Dommer DH, Gazzolo PJ, Painter MS, Phillips JB (2008) Magnetic compass orientation by larval Drosophila melanogaster. J Insect Physiol 54:719–726. 10.1016/j.jinsphys.2008.02.00118359039 10.1016/j.jinsphys.2008.02.001
El Kholy SE, El Husseiny EM (2013) Effect of 60 minutes exposure to electromagnetic field on fecundity, learning and memory, speed of movement and whole body protein of the fruit fly Drosophila melanogaster. JESP 42:639–684. 10.12816/0006347
El Shoura SM Ultrastructure of the synganglion in the larval tick Amblyomma americanum (Ixodoidea: Ixodidae) Exp Appl Acarol 1989 7 239 244 10.1007/BF01194063
El Shoura SM (1989) Ultrastructure of the synganglion in the larval tick Amblyomma americanum (Ixodoidea: Ixodidae). Exp Appl Acarol 7:239–244. 10.1007/BF0119406310.1007/BF01194063
England SJ Lihou K Robert D Static electricity passively attracts ticks onto hosts Curr Biol 2023 33 3041 3047.e4 10.1016/j.cub.2023.06.021 37392744
England SJ, Lihou K, Robert D (2023) Static electricity passively attracts ticks onto hosts. Curr Biol 33:3041-3047.e4. 10.1016/j.cub.2023.06.02137392744 10.1016/j.cub.2023.06.021
Frątczak M Vargová B Tryjanowski P Infected Ixodes ricinus ticks are attracted by electromagnetic radiation of 900 MHz Ticks Tick Borne Dis 2020 11 101416 10.1016/j.ttbdis.2020.101416 32209348
Frątczak M, Vargová B, Tryjanowski P et al (2020) Infected Ixodes ricinus ticks are attracted by electromagnetic radiation of 900 MHz. Ticks Tick Borne Dis 11:101416. 10.1016/j.ttbdis.2020.10141632209348 10.1016/j.ttbdis.2020.101416
Harsanyi P, Scott K, Easton BAA, et al (2022) The effects of anthropogenic electromagnetic fields (EMF) on the early development of two commercially important crustaceans, European lobster, Homarus gammarus (L.) and edible crab, Cancer pagurus (L.). JMSE 10:564. 10.3390/jmse10050564
Herssens H Toribio D De Borre E Thielens A Whole-body averaged absorbed power in insects exposed to far-field radio frequency electromagnetic fields IEEE Trans Antennas Propagat 2022 70 11070 11078 10.1109/TAP.2022.3209201
Herssens H, Toribio D, De Borre E, Thielens A (2022) Whole-body averaged absorbed power in insects exposed to far-field radio frequency electromagnetic fields. IEEE Trans Antennas Propagat 70:11070–11078. 10.1109/TAP.2022.320920110.1109/TAP.2022.3209201
Heylen D Lasters R Adriaensen F Ticks and tick-borne diseases in the city: role of landscape connectivity and green space characteristics in a metropolitan area Sci Total Environ 2019 670 941 949 10.1016/j.scitotenv.2019.03.235 30921726
Heylen D, Lasters R, Adriaensen F et al (2019) Ticks and tick-borne diseases in the city: role of landscape connectivity and green space characteristics in a metropolitan area. Sci Total Environ 670:941–949. 10.1016/j.scitotenv.2019.03.23530921726 10.1016/j.scitotenv.2019.03.235
Hummel NA Li AY Witt CM Serotonin-like immunoreactivity in the central nervous system of two ixodid tick species Exp Appl Acarol 2007 43 265 278 10.1007/s10493-007-9120-z 18040871
Hummel NA, Li AY, Witt CM (2007) Serotonin-like immunoreactivity in the central nervous system of two ixodid tick species. Exp Appl Acarol 43:265–278. 10.1007/s10493-007-9120-z18040871 10.1007/s10493-007-9120-z
Koči J Šimo L Park Y Validation of internal reference genes for real-time quantitative polymerase chain reaction studies in the tick, Ixodes scapularis (Acari: Ixodidae) J Med Entomol 2013 50 79 84 10.1603/ME12034 23427655
Koči J, Šimo L, Park Y (2013) Validation of internal reference genes for real-time quantitative polymerase chain reaction studies in the tick, Ixodes scapularis (Acari: Ixodidae). J Med Entomol 50:79–84. 10.1603/ME1203423427655 10.1603/ME12034
Kokot A Metze D Mouchet N α-Melanocyte-stimulating hormone counteracts the suppressive effect of UVB on Nrf2 and Nrf-dependent gene expression in human skin Endocrinol 2009 150 3197 3206 10.1210/en.2008-1315
Kokot A, Metze D, Mouchet N et al (2009) α-Melanocyte-stimulating hormone counteracts the suppressive effect of UVB on Nrf2 and Nrf-dependent gene expression in human skin. Endocrinol 150:3197–3206. 10.1210/en.2008-131510.1210/en.2008-1315
Leonovich SA Structure of Haller’s organ and taxonomy of hard ticks of the subfamily ixodinae (family Ixodidae) Entmol Rev 2020 100 1387 1401 10.1134/S0013873820090122
Leonovich SA (2020) Structure of Haller’s organ and taxonomy of hard ticks of the subfamily ixodinae (family Ixodidae). Entmol Rev 100:1387–1401. 10.1134/S001387382009012210.1134/S0013873820090122
Lerchl A Klose M Grote K Tumor promotion by exposure to radiofrequency electromagnetic fields below exposure limits for humans BBRC 2015 459 585 590 10.1016/j.bbrc.2015.02.151 25749340
Lerchl A, Klose M, Grote K et al (2015) Tumor promotion by exposure to radiofrequency electromagnetic fields below exposure limits for humans. BBRC 459:585–590. 10.1016/j.bbrc.2015.02.15125749340 10.1016/j.bbrc.2015.02.151
Li Y Sun C Zhou H Extremely low-frequency electromagnetic field impairs the development of honeybee (Apis cerana) Animals 2022 12 2420 10.3390/ani12182420 36139284
Li Y, Sun C, Zhou H et al (2022) Extremely low-frequency electromagnetic field impairs the development of honeybee (Apis cerana). Animals 12:2420. 10.3390/ani1218242036139284 10.3390/ani12182420
Liu Q Si T Xu X Electromagnetic radiation at 900 MHz induces sperm apoptosis through bcl-2, bax and caspase-3 signaling pathways in rats Reprod Health 2015 12 65 10.1186/s12978-015-0062-3 26239320
Liu Q, Si T, Xu X et al (2015) Electromagnetic radiation at 900 MHz induces sperm apoptosis through bcl-2, bax and caspase-3 signaling pathways in rats. Reprod Health 12:65. 10.1186/s12978-015-0062-326239320 10.1186/s12978-015-0062-3
Livak KJ Schmittgen TD Analysis of relative gene expression data using real-time quantitative PCR and the 2−ΔΔCT method Methods 2001 25 402 408 10.1006/meth.2001.1262 11846609
Livak KJ, Schmittgen TD (2001) Analysis of relative gene expression data using real-time quantitative PCR and the 2−ΔΔCT method. Methods 25:402–408. 10.1006/meth.2001.126211846609 10.1006/meth.2001.1262
Medlock JM Hansford KM Bormane A Driving forces for changes in geographical distribution of Ixodes ricinus ticks in Europe Parasites Vectors 2013 6 1 10.1186/1756-3305-6-1 23281838
Medlock JM, Hansford KM, Bormane A et al (2013) Driving forces for changes in geographical distribution of Ixodes ricinus ticks in Europe. Parasites Vectors 6:1. 10.1186/1756-3305-6-123281838 10.1186/1756-3305-6-1
Menezes KMF Oliveira Filho JGD Ferreira LL Borges LMF First neuronal projection from Haller’s organ to the synganglion and three-dimensional reconstruction of Amblyomma sculptum olfactory lobe Ticks Tick Borne Dis 2021 12 101690 10.1016/j.ttbdis.2021.101690 33667831
Menezes KMF, Oliveira Filho JGD, Ferreira LL, Borges LMF (2021) First neuronal projection from Haller’s organ to the synganglion and three-dimensional reconstruction of Amblyomma sculptum olfactory lobe. Ticks Tick Borne Dis 12:101690. 10.1016/j.ttbdis.2021.10169033667831 10.1016/j.ttbdis.2021.101690
Migdal P Bieńkowski P Cebrat M Exposure to a 900 MHz electromagnetic field induces a response of the honey bee organism on the level of enzyme activity and the expression of stress-related genes PLoS ONE 2023 18 e0285522 10.1371/journal.pone.0285522 37172069
Migdal P, Bieńkowski P, Cebrat M et al (2023) Exposure to a 900 MHz electromagnetic field induces a response of the honey bee organism on the level of enzyme activity and the expression of stress-related genes. PLoS ONE 18:e0285522. 10.1371/journal.pone.028552237172069 10.1371/journal.pone.0285522
Ministry of Health of Slovak Republic (2007) Act. no. 537/2007
Mitchell RD Zhu J Carr AL Infrared light detection by the Haller’s organ of adult American dog ticks, Dermacentor variabilis (Ixodida: Ixodidae) Ticks Tick Borne Dis 2017 8 764 771 10.1016/j.ttbdis.2017.06.001 28647127
Mitchell RD, Zhu J, Carr AL et al (2017) Infrared light detection by the Haller’s organ of adult American dog ticks, Dermacentor variabilis (Ixodida: Ixodidae). Ticks Tick Borne Dis 8:764–771. 10.1016/j.ttbdis.2017.06.00128647127 10.1016/j.ttbdis.2017.06.001
Molina-Montenegro MA, Acuña-Rodríguez IS, Ballesteros GI, et al (2023) Electromagnetic fields disrupt the pollination service by honeybees. Sci Adv 9:eadh1455. 10.1126/sciadv.adh1455
Neupert S Predel R Russell WK Identification of tick periviscerokinin, the first neurohormone of Ixodidae: single cell analysis by means of MALDI-TOF/TOF mass spectrometry BBRC 2005 338 1860 1864 10.1016/j.bbrc.2005.10.165 16289040
Neupert S, Predel R, Russell WK et al (2005) Identification of tick periviscerokinin, the first neurohormone of Ixodidae: single cell analysis by means of MALDI-TOF/TOF mass spectrometry. BBRC 338:1860–1864. 10.1016/j.bbrc.2005.10.16516289040 10.1016/j.bbrc.2005.10.165
Newland PL Al Ghamdi MS Sharkh S Exposure to static electric fields leads to changes in biogenic amine levels in the brains of Drosophila Proc Royal Soc 2015 282 20151198 10.1098/rspb.2015.1198
Newland PL, Al Ghamdi MS, Sharkh S et al (2015) Exposure to static electric fields leads to changes in biogenic amine levels in the brains of Drosophila. Proc Royal Soc 282:20151198. 10.1098/rspb.2015.119810.1098/rspb.2015.1198
Panagopoulos DJ Effect of microwave exposure on the ovarian development of Drosophila melanogaster Cell Biochem Biophys 2012 63 121 132 10.1007/s12013-012-9347-0 22367734
Panagopoulos DJ (2012) Effect of microwave exposure on the ovarian development of Drosophila melanogaster. Cell Biochem Biophys 63:121–132. 10.1007/s12013-012-9347-022367734 10.1007/s12013-012-9347-0
Panagopoulos DJ Johansson O Carlo GL Polarization: A Key Difference between man-made and natural electromagnetic fields, in regard to biological activity Sci Rep 2015 5 14914 10.1038/srep14914 26456585
Panagopoulos DJ, Johansson O, Carlo GL (2015) Polarization: A Key Difference between man-made and natural electromagnetic fields, in regard to biological activity. Sci Rep 5:14914. 10.1038/srep1491426456585 10.1038/srep14914
Panagopoulos DJ Johansson O Carlo GL Evaluation of specific absorption rate as a dosimetric quantity for electromagnetic fields bioeffects PLoS ONE 2013 8 e62663 10.1371/journal.pone.0062663 23750202
Panagopoulos DJ, Johansson O, Carlo GL (2013) Evaluation of specific absorption rate as a dosimetric quantity for electromagnetic fields bioeffects. PLoS ONE 8:e62663. 10.1371/journal.pone.006266323750202 10.1371/journal.pone.0062663
Parivar K Kouchesfehani MH Boojar MMA Hayati RN Organ culture studies on the development of mouse embryo limb buds under EMF influence Int J Radiat Biol 2006 82 455 464 10.1080/09553000600863056 16882617
Parivar K, Kouchesfehani MH, Boojar MMA, Hayati RN (2006) Organ culture studies on the development of mouse embryo limb buds under EMF influence. Int J Radiat Biol 82:455–464. 10.1080/0955300060086305616882617 10.1080/09553000600863056
Perez SM Taylor OR Jander R The effect of a strong magnetic field on monarch butterfly (Danaus plexippus) migratory behavior Naturwissenschaften 1999 103 217 240
Perez SM, Taylor OR, Jander R (1999) The effect of a strong magnetic field on monarch butterfly (Danaus plexippus) migratory behavior. Naturwissenschaften 103:217–240
Phillips JL Singh NP Lai H Electromagnetic Fields and DNA Damage Pathophysiol 2009 16 79 88 10.1016/j.pathophys.2008.11.005
Phillips JL, Singh NP, Lai H (2009) Electromagnetic Fields and DNA Damage Pathophysiol 16:79–88. 10.1016/j.pathophys.2008.11.00510.1016/j.pathophys.2008.11.005
Port M Abend M Römer B Van Beuningen D Influence of high-frequency electromagnetic fields on different modes of cell death and gene expression Int J Radiat Biol 2003 79 701 708 10.1080/09553000310001606803 14703943
Port M, Abend M, Römer B, Van Beuningen D (2003) Influence of high-frequency electromagnetic fields on different modes of cell death and gene expression. Int J Radiat Biol 79:701–708. 10.1080/0955300031000160680314703943 10.1080/09553000310001606803
Saliev T Mustapova Z Kulsharova G Therapeutic potential of electromagnetic fields for tissue engineering and wound healing Cell Prolif 2014 47 485 493 10.1111/cpr.12142 25319486
Saliev T, Mustapova Z, Kulsharova G et al (2014) Therapeutic potential of electromagnetic fields for tissue engineering and wound healing. Cell Prolif 47:485–493. 10.1111/cpr.1214225319486 10.1111/cpr.12142
Shepherd S Jackson CW Sharkh SM Extremely low-frequency electromagnetic fields entrain locust wingbeats Bioelectromagnetics 2021 42 296 308 10.1002/bem.22336 33822398
Shepherd S, Jackson CW, Sharkh SM et al (2021) Extremely low-frequency electromagnetic fields entrain locust wingbeats. Bioelectromagnetics 42:296–308. 10.1002/bem.2233633822398 10.1002/bem.22336
Shepherd S Lima MAP Oliveira EE Extremely low frequency electromagnetic fields impair the cognitive and motor abilities of honey bees Sci Rep 2018 8 7932 10.1038/s41598-018-26185-y 29785039
Shepherd S, Lima MAP, Oliveira EE et al (2018) Extremely low frequency electromagnetic fields impair the cognitive and motor abilities of honey bees. Sci Rep 8:7932. 10.1038/s41598-018-26185-y29785039 10.1038/s41598-018-26185-y
Šimo L Koči J Park Y Receptors for the neuropeptides, myoinhibitory peptide and SIFamide, in control of the salivary glands of the blacklegged tick Ixodes scapularis Insect Biochem Mol Biol 2013 43 376 387 10.1016/j.ibmb.2013.01.002 23357681
Šimo L, Koči J, Park Y (2013) Receptors for the neuropeptides, myoinhibitory peptide and SIFamide, in control of the salivary glands of the blacklegged tick Ixodes scapularis. Insect Biochem Mol Biol 43:376–387. 10.1016/j.ibmb.2013.01.00223357681 10.1016/j.ibmb.2013.01.002
Šimo L Park Y Neuropeptidergic control of the hindgut in the black-legged tick Ixodes scapularis Int J Parasitol 2014 44 819 826 10.1016/j.ijpara.2014.06.007 25058510
Šimo L, Park Y (2014) Neuropeptidergic control of the hindgut in the black-legged tick Ixodes scapularis. Int J Parasitol 44:819–826. 10.1016/j.ijpara.2014.06.00725058510 10.1016/j.ijpara.2014.06.007
Šimo L Slovák M Park Y Žitňan D Identification of a complex peptidergic neuroendocrine network in the hard tick, Rhipicephalus appendiculatus Cell Tissue Res 2009 335 639 655 10.1007/s00441-008-0731-4 19082627
Šimo L, Slovák M, Park Y, Žitňan D (2009a) Identification of a complex peptidergic neuroendocrine network in the hard tick, Rhipicephalus appendiculatus. Cell Tissue Res 335:639–655. 10.1007/s00441-008-0731-419082627 10.1007/s00441-008-0731-4
Šimo L, Žitňan D, Park Y (2009b) Two novel neuropeptides in innervation of the salivary glands of the black-legged tick, Ixodes scapularis : myoinhibitory peptide and SIFamide. J Comp Neurol 517:spc1. 10.1002/cne.22230
Šofranková L Baňas M Pipová N Effects of electromagnetic radiation on neuropeptide transcript levels in the synganglion of Ixodes ricinus Pathogens 2023 12 1398 10.3390/pathogens12121398 38133283
Šofranková L, Baňas M, Pipová N et al (2023) Effects of electromagnetic radiation on neuropeptide transcript levels in the synganglion of Ixodes ricinus. Pathogens 12:1398. 10.3390/pathogens1212139838133283 10.3390/pathogens12121398
Szlendak E Oliver JH Anatomy of synganglia, including their neurosecretory regions, in unfed, virgin female Ixodes scapularis say (Acari: Ixodidae) J Morphol 1992 213 349 364 10.1002/jmor.1052130308 1404406
Szlendak E, Oliver JH (1992) Anatomy of synganglia, including their neurosecretory regions, in unfed, virgin female Ixodes scapularis say (Acari: Ixodidae). J Morphol 213:349–364. 10.1002/jmor.10521303081404406 10.1002/jmor.1052130308
Vácha M Drštková D Půžová T Tenebrio beetles use magnetic inclination compass Naturwissenschaften 2008 95 761 765 10.1007/s00114-008-0377-9 18404256
Vácha M, Drštková D, Půžová T (2008) Tenebrio beetles use magnetic inclination compass. Naturwissenschaften 95:761–765. 10.1007/s00114-008-0377-918404256 10.1007/s00114-008-0377-9
Valadez-Lira JA Medina-Chavez NO Orozco-Flores AA Alterations of immune parameters on Trichoplusia ni (Lepidoptera: Noctuidae) larvae exposed to extremely low-frequency electromagnetic fields Environ Entomol 2017 46 376 382 10.1093/ee/nvx037 28334331
Valadez-Lira JA, Medina-Chavez NO, Orozco-Flores AA et al (2017) Alterations of immune parameters on Trichoplusia ni (Lepidoptera: Noctuidae) larvae exposed to extremely low-frequency electromagnetic fields. Environ Entomol 46:376–382. 10.1093/ee/nvx03728334331 10.1093/ee/nvx037
Vancová M Bílý T Nebesářová J Ultrastructural mapping of salivary gland innervation in the tick Ixodes ricinus Sci Rep 2019 9 6860 10.1038/s41598-019-43284-6 31048723
Vancová M, Bílý T, Nebesářová J et al (2019) Ultrastructural mapping of salivary gland innervation in the tick Ixodes ricinus. Sci Rep 9:6860. 10.1038/s41598-019-43284-631048723 10.1038/s41598-019-43284-6
Vargová B, Kurimský J, Cimbala R, et al (2017) Ticks and radio-frequency signals: behavioural response of ticks (Dermacentor reticulatus) in a 900 MHz electromagnetic field. Syst Appl Acarol 22:683–693. 10.11158/saa.22.5.7
Vargová B Majláth I Kurimský J Electromagnetic radiation and behavioural response of ticks: an experimental test Exp Appl Acarol 2018 75 85 95 10.1007/s10493-018-0253-z 29605834
Vargová B, Majláth I, Kurimský J et al (2018) Electromagnetic radiation and behavioural response of ticks: an experimental test. Exp Appl Acarol 75:85–95. 10.1007/s10493-018-0253-z29605834 10.1007/s10493-018-0253-z
Vargová B, Majláth I, Kurimský J, et al (2022) Locomotor activity of Ixodes ricinus females in 900 MHz electromagnetic field. Life 12:. 10.3390/life12060884
Vijver MG Bolte JFB Evans TR Investigating short-term exposure to electromagnetic fields on reproductive capacity of invertebrates in the field situation Electromagn Biol Med 2014 33 21 28 10.3109/15368378.2013.783846 23781930
Vijver MG, Bolte JFB, Evans TR et al (2014) Investigating short-term exposure to electromagnetic fields on reproductive capacity of invertebrates in the field situation. Electromagn Biol Med 33:21–28. 10.3109/15368378.2013.78384623781930 10.3109/15368378.2013.783846
Wang Y, Jiang Z, Zhang L, et al (2022) 3.5-GHz radiofrequency electromagnetic radiation promotes the development of Drosophila melanogaster. Environ Pollut 294:118646. 10.1016/j.envpol.2021.118646
Wust P Kortüm B Strauss U Non-thermal effects of radiofrequency electromagnetic fields Sci Rep 2020 10 13488 10.1038/s41598-020-69561-3 32778682
Wust P, Kortüm B, Strauss U et al (2020) Non-thermal effects of radiofrequency electromagnetic fields. Sci Rep 10:13488. 10.1038/s41598-020-69561-332778682 10.1038/s41598-020-69561-3
Wyszkowska J Shepherd S Sharkh S Exposure to extremely low frequency electromagnetic fields alters the behaviour, physiology and stress protein levels of desert locusts Sci Rep 2016 6 36413 10.1038/srep36413 27808167
Wyszkowska J, Shepherd S, Sharkh S et al (2016) Exposure to extremely low frequency electromagnetic fields alters the behaviour, physiology and stress protein levels of desert locusts. Sci Rep 6:36413. 10.1038/srep3641327808167 10.1038/srep36413
Zbojovský J Pavlík M Cimbala R Kurimský J Merania elektromagnetických polí v okolí vybraných telekomunikačných vysielačov v lokalitách Košice a okolie Zborník Príspevkov Prednesených na Vedeckom Seminári EMITICK22 2022 Stará Lesná, Slovakia Technická univerzita v Košiciach 33 38
Zbojovský J, Pavlík M, Cimbala R, Kurimský J (2022) Merania elektromagnetických polí v okolí vybraných telekomunikačných vysielačov v lokalitách Košice a okolie. Zborník Príspevkov Prednesených na Vedeckom Seminári EMITICK22. Technická univerzita v Košiciach, Stará Lesná, Slovakia, pp 33–38
Zhao R Zhang S Xu Z Studying gene expression profile of rat neuron exposed to 1800MHz radiofrequency electromagnetic fields with cDNA microassay Toxicology 2007 235 167 175 10.1016/j.tox.2007.03.015 17449163
Zhao R, Zhang S, Xu Z et al (2007) Studying gene expression profile of rat neuron exposed to 1800MHz radiofrequency electromagnetic fields with cDNA microassay. Toxicology 235:167–175. 10.1016/j.tox.2007.03.01517449163 10.1016/j.tox.2007.03.015
Zielinski J Ducray AD Moeller AM Effects of pulse-modulated radiofrequency magnetic field (RF-EMF) exposure on apoptosis, autophagy, oxidative stress and electron chain transport function in human neuroblastoma and murine microglial cells In Vitro Toxicol 2020 68 104963 10.1016/j.tiv.2020.104963
Zielinski J, Ducray AD, Moeller AM et al (2020) Effects of pulse-modulated radiofrequency magnetic field (RF-EMF) exposure on apoptosis, autophagy, oxidative stress and electron chain transport function in human neuroblastoma and murine microglial cells. In Vitro Toxicol 68:104963. 10.1016/j.tiv.2020.10496310.1016/j.tiv.2020.104963
