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

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 thermal stress on activity of corpora allata and dorsolateral neurosecretory neurons in Morimus funereus larvae

The effects of different temperatures (23°C and 8°C) on activity of corpora allata (CA) and dorsolateral (L1, L2) protocerebral neurosecretory neurons were investigated in Morimus funereus Mulsant (1863) larvae collected from a natural population during March. Activity of CA was revealed by monitoring of CA volume and cell number. Increase of CA volume after two day exposure to both temperatures was shown to be the result of increase in cell number. Activity of CA was higher at 23°C than 8°C. Activity of L1 and L2 neurosecretory neurons was inhibited at both temperatures. Neurosecretory neurons were more sensitive to temperature of 23°C than 8°C. It can be supposed that dorsolateral neurosecretory neurons synthesize neurohormones that affect CA activity, depending on environmental temperature.Ispitivan je uticaj različitih temperatura (23°C i 8°C) na aktivnost corpora allata (CA) i dorzolateralnih (L1 i L2) protocerebralnih neurosekretnih neurona kod larvi Morimus funereus Muls. (1863), sakupljenih iz prirode tokom meseca marta. Aktivnost CA je procenjivana praćenjem promena veličine CA i broja ćelija CA. Pokazano je da je povećanje veličine CA, nakon 2 dana izlaganja larvi obema temperaturama, rezultuje u povećanju broja ćelija. Aktivnost CA je veća na temperaturi od 230C, nego na 80C. Aktivnost L1 i L2 neurosekretnih neurona je bila inhibirana delovanjem obeju temperatura. Neurosekretni neuroni su osetljiviji na delovanje temperature od 230C, nego na 80C. Moglo bi se pretpostaviti da dorzolateralni neurosekretni neuroni sintetišu neurohormone koji utiču na aktivnost CA, u zavisnosti od temperature spoljašnje sredine.Projekat ministarstva br. 161

The embryonic and post-embryonic development in two Drosophila species exposed to the static magnetic field of 60 mT

In this study, a static magnetic field influence on development and viability in two different species, Drosophila melanogaster and Drosophila hydei, was investigated. Both species completed development (egg--adult), in and out of the static magnetic field induced by double horseshoe magnet. Treated vials with eggs were placed in the gap between magnetic poles (47 mm) and exposed to the average magnetic induction of 60 mT, while control ones were kept far enough from magnetic field source. We found that exposure to the static magnetic field reduced development time in both species, but statistical significance was found only for D. hydei. Furthermore, we found that the average viability of both Drosophila species exposed to the magnetic field was significantly weaker compared to control ones. These results indicate that 60 mT static magnetic field could be considered as a potential stressor, influencing on different levels the embryonic and post-embryonic development of individuals.</.Ministry of Education and Science Development, Republic of Serbia [173012, 173027

Comparative examinations of magnetic field effects on pupal development in three holometabolous insect species

The development of new technologies in the last decades has actuated researches on effects of magnetic and electromagnetic fields on individual performance and physiological reactions in living systems. Our work is based on the model of pupal development and compares insect species belonging to different orders: Tenebrio molitor (Coleoptera), Drosophila melanogaster (Diptera) and Apis mellifera (Hymenoptera). A highly significant increase in the rate of adult eclosion was detected in all examined species reared under constant external magnetic field suggesting unique mechanisms of magnetic field influence on development of three evolutionary distant insect species.Razvoj novih tehnologija poslednjih decenija je pokrenuo istraživanja efekata magnetnih i elektromagnetnih polja na individualnu performansu i fiziološke reakcije u živim sistemima. Naš rad je baziran na modelu lutkinog razvića i poredi tri evolutivno udaljene vrste insekata koje pripadaju različitim redovima: Tenebrio molitor (Coleoptera), Drosophila melanogaster (Diptera) i Apis mellifera (Hymenoptera). Kod svih proučavanih vrsta je uočen statistički značajan porast brzine izleganja adulta pod uticajem spoljašnjeg magnetnog polja što ukazuje na jedinstvene mehanizme delovanja na procese razviće kod tri udaljene vrste insekata.nul

The embryonic and post-embryonic development in two Drosophila species exposed to the static magnetic field of 60 mT

In this study, a static magnetic field influence on development and viability in two different species, Drosophila melanogaster and Drosophila hydei, was investigated. Both species completed development (egg--adult), in and out of the static magnetic field induced by double horseshoe magnet. Treated vials with eggs were placed in the gap between magnetic poles (47 mm) and exposed to the average magnetic induction of 60 mT, while control ones were kept far enough from magnetic field source. We found that exposure to the static magnetic field reduced development time in both species, but statistical significance was found only for D. hydei. Furthermore, we found that the average viability of both Drosophila species exposed to the magnetic field was significantly weaker compared to control ones. These results indicate that 60 mT static magnetic field could be considered as a potential stressor, influencing on different levels the embryonic and post-embryonic development of individuals.</.Ministry of Education and Science Development, Republic of Serbia [173012, 173027

Comparative examinations of magnetic field effects on pupal development in three holometabolous insect species

The development of new technologies in the last decades has actuated researches on effects of magnetic and electromagnetic fields on individual performance and physiological reactions in living systems. Our work is based on the model of pupal development and compares insect species belonging to different orders: Tenebrio molitor (Coleoptera), Drosophila melanogaster (Diptera) and Apis mellifera (Hymenoptera). A highly significant increase in the rate of adult eclosion was detected in all examined species reared under constant external magnetic field suggesting unique mechanisms of magnetic field influence on development of three evolutionary distant insect species.Razvoj novih tehnologija poslednjih decenija je pokrenuo istraživanja efekata magnetnih i elektromagnetnih polja na individualnu performansu i fiziološke reakcije u živim sistemima. Naš rad je baziran na modelu lutkinog razvića i poredi tri evolutivno udaljene vrste insekata koje pripadaju različitim redovima: Tenebrio molitor (Coleoptera), Drosophila melanogaster (Diptera) i Apis mellifera (Hymenoptera). Kod svih proučavanih vrsta je uočen statistički značajan porast brzine izleganja adulta pod uticajem spoljašnjeg magnetnog polja što ukazuje na jedinstvene mehanizme delovanja na procese razviće kod tri udaljene vrste insekata.nul

The effect of a static magnetic field on the morphometric characteristics of neurosecretory neurons and corpora allata in the pupae of yellow mealworm Tenebrio molitor (Tenebrionidae)

Purpose: The morphometric characteristics of A1 and A2 protocerebral neurosecretory neurons (cell and nuclei size, number of nucleoli in the nuclei); corpora allata size, nuclei size, cell number, were investigated in the pupae of yellow mealworm, Tenebrio molitor (L.), exposed to a strong static magnetic field of 320 mT maximum induction (10,000 times higher than the Earth's). Materials and methods: The experimental groups of Tenebrio molitor pupae were: A control group exposed only to natural magnetic field and sacrificed at the eighth day of pupal development (C); and pupae kept in a strong static magnetic field for eight days and then sacrificed (MF). Serial brain cross-sections were stained using the Alcian Blue Floxin technique. All the parameters were analyzed and measurements were performed using an image processing and analysis system (Leica, Cambridge, UK) linked to a Leica DMLB light microscope (program is QWin - Leica's Quantimet Windows-based image analysis tool kit). Results: The values of morphometric parameters of neurosecretory neurons and corpora allata were significantly increased after exposure of the pupae to the strong magnetic field. Conclusions: The strong magnetic field influence characteristics of protocerebral neurosecretory neurons and corpora allata in the late Tenebrio molitor pupae.nul

The effect of a static magnetic field on the morphometric characteristics of neurosecretory neurons and corpora allata in the pupae of yellow mealworm Tenebrio molitor (Tenebrionidae)

Purpose: The morphometric characteristics of A1 and A2 protocerebral neurosecretory neurons (cell and nuclei size, number of nucleoli in the nuclei); corpora allata size, nuclei size, cell number, were investigated in the pupae of yellow mealworm, Tenebrio molitor (L.), exposed to a strong static magnetic field of 320 mT maximum induction (10,000 times higher than the Earth's). Materials and methods: The experimental groups of Tenebrio molitor pupae were: A control group exposed only to natural magnetic field and sacrificed at the eighth day of pupal development (C); and pupae kept in a strong static magnetic field for eight days and then sacrificed (MF). Serial brain cross-sections were stained using the Alcian Blue Floxin technique. All the parameters were analyzed and measurements were performed using an image processing and analysis system (Leica, Cambridge, UK) linked to a Leica DMLB light microscope (program is QWin - Leica's Quantimet Windows-based image analysis tool kit). Results: The values of morphometric parameters of neurosecretory neurons and corpora allata were significantly increased after exposure of the pupae to the strong magnetic field. Conclusions: The strong magnetic field influence characteristics of protocerebral neurosecretory neurons and corpora allata in the late Tenebrio molitor pupae.nul

The effect of extremely low-frequency magnetic field on motor activity of rats in the open field

Exposure to extremely low-frequency magnetic field (ELF-MF, 50 Hz, 0.5 mT) for seven days did not change spontaneous motor activity of rats in the open field compared to sham-exposed animals. Pre-exposure to ELF-MF decreased locomotor and stereotypic activity induced by amphetamine (1.5 mg/kg body weight) and accordingly increased the resting time compared to sham-exposed and amphetamine-treated rats. Vertical activity (rearing) of these two groups was similar. Our results indicate that ELF-MF has different effects on some parameters of amphetamine-induced motor activity, probably due to brain region-specific effects on catecholaminergic systems responsible for movement control.nul