The influence of electromagnetic field (2 mT, 50 Hz) on spontaneous bioelectrical activity of antennal lobe neurons of adult Morimus funereus (Insecta, Coleoptera)

Spoljašnja magnetna polja (MP) narušavaju ravnotežu bioloških sistema, čak i tokom kraćeg vremena izlaganja, što za posledicu ima poremećaje na različitim nivoima organizacije. Na ovaj način nastali poremaćaji akumuliraju se u organizmima, što je jedan od razloga za traženje objašnjenja bioloških efekata MP. S druge strane, veoma važna činjenica koja nas usmerava na što bolje razumevanje ove problematike je potreba za zaštitom ljudskog zdravlja zbog uvođenja novih tehnologija u svakodnevni život, industriju i medicinu, kao i zbog terapijske upotrebe MP. Pretpostavka je da se interakcija spoljašnjih MP i organizama dešava na svim nivoima organizacije, uključujući i nervni sistem. Stoga je cilj ovih istraživanja bio ispitivanje uticaja elektromagnetnog polja (2 mT, 50 Hz) različitih karakteristika (trajanje, talasni oblik) na spontanu bioelektričnu aktivnost neurona antenalnog lobusa adulta Morimus funereus. Aktivnost neurona (pozadinskih/neuronske populacije i najbližih registrujućoj elektrodi) je registrovana kroz nekoliko faza u kojima smo adulte izlagali sinusoidalnom ili kvadratnom MP različitog trajanja: 5, 10 i 15 min (MP-5, MP-10, MP-15, respektivno). Uticaj MP smo procenjivali na osnovu promena u neuronskoj aktivnosti, a procenjivali smo i (i)reverzibilnost promena između tripleta formiranih od određenih eksperimentalnih faza. U tripletima koji slede vremenski tok eksperimenta, a podrazumevaju delovanje MP određenog trajanja (MP-5, MP-10 i MP-15, respektivno), testirali smo i njihove međusobne razlike. Rezultati istraživanja su pokazali da primenjeno MP, bez obzira na dužinu izlaganja i talasni oblik, menja aktivnost neurona antenalnog lobusa. U sinusoidalnom MP, te promene su najizraženije nakon delovanja MP-15, a u kvadratnom MP, nakon delovanja MP-5. Pokazano je da je kontrolna aktivnosti pozadinskih neurona značajno promenjene nakon delovanja sinusoidalnog MP-5, kao i nakon delovanja MP-10, a značajno je manja nakon delovanja MP-15. S druge strane, sinusoidalno MP, bez obzira na dužinu izlaganja izaziva značajnu inhibiciju kontrolne aktivnosti najbližih neurona...External magnetic fields (MF) disturb the equilibrium of biological systems, even during short-term exposure, resulting in disturbances at different levels of organization. These changes accumulate in organisms, which is one of the reasons for testing biological effects of MF. On the other hand, the fact that modern man is exposed to increasing number of MF sources due to the use of new technologies in everyday life, industry, medicine, as well as therapeutic application of MF, makes this topic even more important, in terms of human health protection. It is assumed that the interaction between external MF and organisms takes place at all levels of organization, including the nervous system. Thus, the aim of this study was to investigate the influence of electromagnetic field (EMF) of different characteristics (exposure duration, waveform) on spontaneous bioelectrical activity of antennal lobe neurons of adult Morimus funereus. Neurons activity (background/neuronal population and those nearest to the recording electrode) was registered through several phases of exposure of adult longhorn beetles to sine wave or square wave MF of different exposure duration: 5, 10 and 15 minutes (MP-5, MP-10 and MP-15, respectively). Estimation of MF influence was based on registered changes of neuronal activity. (I)reversibility of such changes was tested through comparison the triplets formed by particular experimental phases. Changes in triplets that follow the time course of the experiment, with reference to MF influence of different exposure duration (MP-5, MP-10 and MP-15, respectively), were also tested. Results of this study showed that the applied MF, regardless of exposure duration and waveform, modifies the activity of antennal lobe neurons. In sine wave MF, the most prominent changes are recorded after MP-15, while in square wave MF such changes were recorded after MP-5. Control activity of the neuronal population was significantly changed both after MP-5 and MP-10, as well as significantly decreased after MP-15. Sine wave MF, regardless of exposure duration, significantly inhibits control activity of nearest neurons..

Viability of old house borer (Hylotrupes bajulus) larvae exposed to a constant magnetic field of 98 mT under laboratory conditions

The purpose of our experiment was to establish how exposure to a constant magnetic field of 98 mT affects behavior in terms of viability and larval mass of the old house borer (Hylotrupes bajulus L.). It is demonstrated that larvae exposed to this magnetic field show statistically significant higher viability, as well as a tendency of mass increase in comparison with the control group. These results can be attributed to the modulatory effect of the employed external magnetic field on metabolism and neurohumoral regulation in the insects.Cilj našeg eksperimenta je bio da se utvrdi kako izlaganje konstantnom magnetnom polju od 98 mT utiče na ponašanje u smislu preživljavanja i mase larvi kućne strižibube (Hylotrupes bajulus L.). Pokazano je da larve koje su se nalazile u magnetnom polju pomenutih karakteristika imaju statistički značajno veće preživljavanje, kao i tendenciju povećanja mase u odnosu na kontrolnu grupu jedinki. Ovi rezultati se mogu pripisati modulatornom uticaju spoljašnjeg magnetnog polja na metabolizam i neurohumoralnu regulaciju insekata.Projekat ministarstva br. 14302

Effect of glutamate antagonists on nitric oxide production in rat brain following intrahippocampal injection

Stimulation of glutamate receptors induces neuronal nitric oxide (NO) release, which in turn modulates glutamate transmission. The involvement of ionotropic glutamate NMDA and AMPA/kainate receptors in induction of NO production in the rat brain was examined after injection of kainate, a non-NMDA receptor agonist; kainate plus 6-cyano- 7-nitroquinoxaline-2,3-dione (CNQX), a selective AMPA/kainate receptor antagonist; or kainate plus 2-amino-5-phosphonopentanoic acid (APV), a selective NMDA receptor antagonist. Competitive glutamate receptor antagonists were injected with kainate unilaterally into the CA3 region of the rat hippocampus. The accumulation of nitrite, the stable metabolite of NO, was measured by the Griess reaction at different times (5 min, 15 min, 2 h, 48 h, and 7 days) in hippocampus, forebrain cortex, striatum, and cerebellum homogenates. The used glutamate antagonists APV and CNQX both provided sufficient neuroprotection in the sense of reducing nitrite concentrations, but with different mechanisms and time dynamics. Our findings suggest that NMDA and AMPA/kainate receptors are differentially involved in nitric oxide production.Stimulacija glutamatskih receptora dovodi do stvaranja azot oksida (NO) u neuronima mozga što dovodi do modulacije glutamatske neurotransmisije. Ispitivana je uloga glutamatskih NMDA i AMPA/kainatnih receptora u stvaranju NO u mozgu pacova posle intracerebralne aplikacija kainata, agonista AMPA/kainatnih receptora, kainata sa 6-ciano-7- nitrokinoksalin-2,3-dionom (CNQX), selektivnim antagonistom AMPA/kainatnih receptora ili kainata sa 2-amino-5-fosfonopentanoiskom kiselinom (APV) selektivnim antagonistom NMDA receptora. Antagonisti glutamata su aplicirani unilateralno u selektivno osetljiv CA3 region hipokampusa. Stvaranje NO je praćeno preko akumulacije nitrita, stabilnih metabolita NO, Griess-ovom metodom. Merenja su vršena u hipokampusu, korteksu, stiatumu i cerebelumu mozga pacova 5 min, 15 min, 2 h, 48 h i 7 dana nakon aplikacije. U svim praćenim moždanim strukturama neuroprotektivno je delovala primena CNQX i APV u smislu smanjenja produkcije NO, ali sa očiglednom razlikom u mehanizmu dejstva i vremenskoj dinamici. Rezultati našeg istraživanja dokazuju da su glutamatski NMDA i AMPA/kainatni receptori različito uključeni u proces produkcije NO.nul

Viability of old house borer (Hylotrupes bajulus) larvae exposed to a constant magnetic field of 98 mT under laboratory conditions

The purpose of our experiment was to establish how exposure to a constant magnetic field of 98 mT affects behavior in terms of viability and larval mass of the old house borer (Hylotrupes bajulus L.). It is demonstrated that larvae exposed to this magnetic field show statistically significant higher viability, as well as a tendency of mass increase in comparison with the control group. These results can be attributed to the modulatory effect of the employed external magnetic field on metabolism and neurohumoral regulation in the insects.Cilj našeg eksperimenta je bio da se utvrdi kako izlaganje konstantnom magnetnom polju od 98 mT utiče na ponašanje u smislu preživljavanja i mase larvi kućne strižibube (Hylotrupes bajulus L.). Pokazano je da larve koje su se nalazile u magnetnom polju pomenutih karakteristika imaju statistički značajno veće preživljavanje, kao i tendenciju povećanja mase u odnosu na kontrolnu grupu jedinki. Ovi rezultati se mogu pripisati modulatornom uticaju spoljašnjeg magnetnog polja na metabolizam i neurohumoralnu regulaciju insekata.Projekat ministarstva br. 14302

Uticaj cimiazol hidrohlorida na mitotsku i proliferativnu aktivnost u kulturama humanih limfocita

Cymiazole hydrochloride is the active ingredient of a synthetic systemically acting acaricide used in beekeeping (Apitol®, Apichem®). Considering that residues of cymiazole hydrochloride were detected in all bee products being used for human nutrition and as alternative medications in human and veterinary medicine, the objective of this study was to evaluate the effects of cymiazole hydrochloride on mitotic activity of cultured human lymphocytes. The mitotic and proliferation indices in phytohaemagglutinin-activated human peripheral blood lymphocytes were determined using three experimental concentrations of cymiazole hydrochloride (0.01; 0.1; 1mg/ml). All experimental concentrations of cymiazole hydrochloride increased mitotic index values (MI) by a statistically highly significant amount (p lt 0.001). Moreover, proliferation index (PI) was also changed very significantly (p lt 0.001) after each experimental cymiazole hydrochloride treatment. The dose dependent increase in proliferation index values clearly demonstrates the ability of cymiazole hydrochloride to induce significant alterations of cell cycle kinetics having an influence on G0 state and arousing cell division. This indicates a risk from consuming bee products with cymiazole hydrochloride residues particularly in those predisposed to malignant diseases. Strict respect to the withrawal time while using cymiazole hydrochloride (Apitol®, Apichem®) is of great importance because residue levels higher than the permitted one can easily occur in honey and other bee products from treated honey bee colonies.Cimiazol hidrohlorid predstavlja aktivnu supstancu sintetičkih akaricida sa sistemskim dejstvom koji se koriste u pčelarstvu (Apitol®, Apichem®). Obzirom da su rezidue cimiazol hidrohlorida detektovane u svim pčelinjim proizvodima, koji se koriste u ishrani i kao alternativni lekovi u humanoj i veterinarskoj medicini, cilj ovog rada bio je ispitivanje efekata cimiazol hidrohlorida na mitotsku i proliferativnu aktivnost humanih limfocita u kulturi. Analizirani su mitotski i proliferativni indeksi humanih limfocita aktiviranih fitohemaglutininom pri čemu su koršćene tri eksperimentalne koncentracije cimiazol hidrohlorida u opsegu od 0.001 mg/ml do 1 mg/ml. Sve tri eksperimentalne koncentracije cimiazol hidrohlorida izazvale su vrlo visoko signifikantno (p lt 0.001) povećanje vrednosti mitotskog indeksa (MI) humanih limfocita. Takođe, vrednosti proliferativnog indeksa (PI) su vrlo visoko signifikantno (p lt 0.001) povećane nakon svakog eksperimentalnog tretmana cimiazol hidrohloridom. Dozno zavisno povećanje vrednosti proliferativnog indeksa jasno pokazuje sposobnost cimiazol hidrohlorida da izazove značajne promene u kinetici ćelijskog ciklusa utičući na G0 tačku i podstičući ćelijsku deobu, što ukazuje na rizik prilikom konzumiranja pčelinjih proizvoda sa reziduama cimiazol hidrohlorida, posebno kod jedinki sklonih malignitetima. Izuzetno je značajno strogo poštovanje karence prilikom upotrebe cimiazol hidrohlorida (Apitol®, Apichem®) jer rezidue, u količini većoj od dozvoljene, mogu veoma lako dospeti u med i druge pčelinje proizvode dobijene od tretiranih pčelinjih društava

Effect of glutamate antagonists on nitric oxide production in rat brain following intrahippocampal injection

Stimulation of glutamate receptors induces neuronal nitric oxide (NO) release, which in turn modulates glutamate transmission. The involvement of ionotropic glutamate NMDA and AMPA/kainate receptors in induction of NO production in the rat brain was examined after injection of kainate, a non-NMDA receptor agonist; kainate plus 6-cyano- 7-nitroquinoxaline-2,3-dione (CNQX), a selective AMPA/kainate receptor antagonist; or kainate plus 2-amino-5-phosphonopentanoic acid (APV), a selective NMDA receptor antagonist. Competitive glutamate receptor antagonists were injected with kainate unilaterally into the CA3 region of the rat hippocampus. The accumulation of nitrite, the stable metabolite of NO, was measured by the Griess reaction at different times (5 min, 15 min, 2 h, 48 h, and 7 days) in hippocampus, forebrain cortex, striatum, and cerebellum homogenates. The used glutamate antagonists APV and CNQX both provided sufficient neuroprotection in the sense of reducing nitrite concentrations, but with different mechanisms and time dynamics. Our findings suggest that NMDA and AMPA/kainate receptors are differentially involved in nitric oxide production.Stimulacija glutamatskih receptora dovodi do stvaranja azot oksida (NO) u neuronima mozga što dovodi do modulacije glutamatske neurotransmisije. Ispitivana je uloga glutamatskih NMDA i AMPA/kainatnih receptora u stvaranju NO u mozgu pacova posle intracerebralne aplikacija kainata, agonista AMPA/kainatnih receptora, kainata sa 6-ciano-7- nitrokinoksalin-2,3-dionom (CNQX), selektivnim antagonistom AMPA/kainatnih receptora ili kainata sa 2-amino-5-fosfonopentanoiskom kiselinom (APV) selektivnim antagonistom NMDA receptora. Antagonisti glutamata su aplicirani unilateralno u selektivno osetljiv CA3 region hipokampusa. Stvaranje NO je praćeno preko akumulacije nitrita, stabilnih metabolita NO, Griess-ovom metodom. Merenja su vršena u hipokampusu, korteksu, stiatumu i cerebelumu mozga pacova 5 min, 15 min, 2 h, 48 h i 7 dana nakon aplikacije. U svim praćenim moždanim strukturama neuroprotektivno je delovala primena CNQX i APV u smislu smanjenja produkcije NO, ali sa očiglednom razlikom u mehanizmu dejstva i vremenskoj dinamici. Rezultati našeg istraživanja dokazuju da su glutamatski NMDA i AMPA/kainatni receptori različito uključeni u proces produkcije NO.nul

Temperature and magnetic field effects on the activity of protocerebral neurosecretory neurons and corpora allata in Cerambyx cerdo L. larvae

The effects of constant temperature and an extremely low-frequency magnetic field (ELFMF, 50 Hz and average induction of 20 mT) on the activity of medial protocerebral neurosecretory neurons (A1 and A2) and corpora allata were investigated in Cerambyx cerdo L. larvae after 30 days of exposure. Both constant temperature of 23°C and the ELFMF led to decrease in activity of A1 and A2 neurosecretory neurons and increase in activity of corpora allata compared to the control group (larvae from natural conditions). The changes are more pronounced in A2 than A1 neurons.Ispitivan je uticaj konstantne temperature i ekstremno niskofrekventnog magnetnog polja (ELFMF, 50 Hz i prosečna indukcija 20mT) na aktivnost medijanih protocerebralnih neurosekretnih neurona (A1 i A2) i corpora allata kod larvi Cerambyx cerdo posle 30 dana izlaganja i konstantna temperatura od 23°C i ELFMF dovode do smanjenja aktivnosti A1 i A2 neurosekretnih neurona i povećanja aktivnosti corpora allata u poređenju sa kontrolnom grupom (larve iz prirodnih uslova). Promene su više izražene kod A2 nego kod A1neurona.nul

Effects of tannic acid on trypsin and leucine aminopeptidase activities in gypsy moth larval midgut

The effects of allelochemical stress on genetic variations in the specific activities of gypsy moth digestive enzymes (trypsin and leucine aminopeptidase) and relative midgut mass (indirect measure of food consumption), as well as variability in their plasticity, were investigated in fifth instar gypsy moths originating from two populations with different trophic adaptations (oak and locust-tree forests). Thirty-two full-sib families from the Quercus population and twenty-six full-sib families from the Robinia population were reared on an artificial diet with or without supplementation with tannic acid. Between population differences were observed as higher average specific activity of trypsin and relative midgut mass in larvae from the Robinia population. Significant broad-sense heritabilities were observed for the specific activity of trypsin in the control state, and for specific activity of leucine aminopeptidase in a stressful environment. Significantly lower heritability for relative midgut mass was recorded in larvae from the Robinia population reared under stressful conditions. Significant variability of trypsin plasticity in larvae from both populations and significant variability of leucine aminopeptidase plasticity in larvae from the Robinia population point to the potential for the evolution of enzyme adaptive plastic responses to the presence of stressor. Non-significant across-environment genetic correlations do not represent a constraint for the evolution of enzyme plasticity. [Projekat Ministarstva nauke Republike Srbije, br. 173027

Effects of different insecticides on the antioxidative defense system of the European Corn Borer (Ostrinia nubilalis Hubner) (Lepidoptera: Crambidae) larvae

The European corn borer (Ostrinia nubilalis) is one of the most important insect pests of maize, and has a significant impact on the production of this crop. In this work, we examined the effects of different insecticides on the antioxidative defense system of O. nubilalis larvae. The experimental setup consisted of a completely randomized block design with 4 replicates. Four experimental groups were formed as follows: control (C), indoxacarb (250 mL ha(-1)), chlorantraniliprole (100 mL ha(-1)) and the chlorantraniliprole+lambda cyhalothrin (200 mL ha(-1)) group. Larvae from maize stems were collected 20 days after insecticide application and the whole larvae were homogenized. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST), and the total amount of free SH groups were assessed. Comparison of the experimental groups showed that indoxacarb significantly affected the activities of GST, GPx and the total amount of free SH groups, while chlorantraniliprole significantly affected the activities of SOD, CAT, GST and the total amount of free SH groups, while chlorantraniliprole+ lambda cyhalothrin significantly affected the activities of CAT, GST and the total amount of free SH groups. The results show that exposure to insecticides considerably affects the antioxidative defense components of the European corn borer larvae, especially chlorantraniliprole (T2)

Influence of a trout farm on antioxidant defense in larvae of Ephemera danica (Insecta: Ephemeroptera)

The aim of this study was to establish the influence of a trout farm on the activity of enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), and total glutathione concentration (GSH), in larvae of Ephemera danica, and on environmental parameters in the receiving watercourse. The investigations were carried out seasonally (April, July, and October of 2016 and January of 2017) at four localities (SK1 - control, and SK2, SK3, and SK4 - 30 m, 330 m and 630 m below the fish farm, respectively) along the Skrapez River. Discharged water had the greatest effect on the concentrations of dissolved oxygen (DO), ammonium ions, nitrates (NO3-), and total phosphorus. In the case of SOD and GSH, seasonal changes were greater than longitudinal, with maximal values attained in spring and summer and minimal in autumn and winter. SOD showed the strongest correlation with DO, and GSH with total nitrogen. Activity of GPx demonstrated greater longitudinal variability with maximum at SK2 in all seasons and the strongest correlation with NO3-. The obtained results indicate that GPx activity was the most sensitive to the trout farm effects, while SOD and GSH were more influenced by natural seasonal changes of environmental parameters