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Purpose: Extremely low frequency (ELF) magnetic fields as essential ecological factors may induce specific responses in genetically different lines. The object of this study was to investigate the impact of the ELF magnetic field on fitness components and locomotor activity of five Drosophila subobscura isofemale (IF) lines., Materials and Methods: Each D. subobscura IF line, arbitrarily named: B16/1, B24/4, B39/1, B57/2 and B69/5, was maintained in five full-sib inbreeding generations. Their genetic structures were defined based on the mitochondrial DNA variability. Egg-first instar larvae and 1-day-old flies were exposed to an ELF magnetic field (50 Hz, 0.5 mT, 48 h) and thereafter, fitness components and locomotor activity of males and females in an open field test were observed for each selected IF line, respectively., Results: Exposure of egg-first instar larvae to an ELF magnetic field shortened developmental time, and did not affect the viability and sex ratio of D. subobscura IF lines. Exposure of 1-day-old males and females IF lines B16/1 and B24/4 to an ELF magnetic field significantly decreased their locomotor activity and this effect lasted longer in females than males., Conclusions: These results indicate various responses of D. subobscura IF lines to the applied ELF magnetic field depending on their genetic background.

Purpose: The aim of this study was to investigate the influence of extremely low frequency magnetic field (ELF-MF) on different behavior parameters (locomotion, stereotypy, and immobility) in 3- and 10-month-old male Mongolian gerbils. Materials and methods: The animals were continuously exposed to ELF-MF (50 Hz; 0.1, 0.25 and 0.5 mT) for seven days. Their behavior was monitored for 60 min in the open field after the 1st, 2nd, 4th, and 7th day of exposure (immediate effect), and three days after ELF-MF exposure had been ceased (delayed effect). Results: In 3-month-old gerbils, exposure to ELF-MF (0.1, 0.25 and 0.5 mT) increased motor behavior (locomotion and stereotypy), and consequently decreased immobility. Additionally, ELF-MF had delayed effect (except 0.25 mT) on stereotypy and immobility. In 10-month-old gerbils, ELF-MF of 0.1, 0.25 and 0.5 mT induced decrease, slight increase, and pronounced stimulation of motor behavior, respectively. Regardless of magnetic induction value, increased motor behavior was observed three days after ELF-MF exposure has been ceased (delayed effect). Conclusions: It can be proposed that the specific temporal patterns of ELF-MF-induced motor behavior changes in 3- and 10-month-old gerbils are a consequence of age-dependent morpho-functional differences in the brain structures responsible for a control of motor behavior. [ABSTRACT FROM AUTHOR]

Changes in the behavior of Morimus funereus individuals were investigated as early manifestations of the contact of a living system with a changed environment primarily established via the nervous system. These experiments were aimed at revealing possible behavioral differences of a laboratory population of cerambycid beetle M. funereus in an "open field" before and after exposure to an extremely low frequency magnetic field (ELF-MF, 50 Hz, 2 mT). The experimental groups were divided into several activity categories and exposed to ELF-MF. The results showed that the activity increased in the groups with medium and low motor activity, but decreased in highly active individuals. High individual variability was found in the experimental groups, as well as differences in motor activities between the sexes, both before and after exposure to ELF-MF. According to preliminary results, we assume the changes of activity in both sexes after exposure to ELF-MF. The results showed a tendency toward locomotor activity decrease, the affect being more pronounced in females. As opposed to this type of activity, stereotypic activity of males was increased after the exposure, whereas females maintained the expected tendency of decrease. However, we did not obtain statistically significant differences because of a high individual variability and a low total number of individuals in the experiment (N = 28). Only a detailed analysis of the locomotor activity at 1-min intervals showed some statistically significant differences in behavior between the sexes. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to evaluate behavioural effects of an extremely low frequency magnetic field (ELF-MF) in 3-month-old Mongolian gerbils submitted to global cerebral ischemia. After 10-min occlusion of both common carotid arteries, the gerbils were placed in the vicinity of an electromagnet and continuously exposed to ELF-MF (50Hz, 0.5mT) for 7 days. Their behaviour (locomotion, stereotypy, rotations, and immobility) was monitored on days 1, 2, 4, 7, and 14 after reperfusion for 60min in the open field. It was shown that the 10-min global cerebral ischemia per se induced a significant motor activity increase (locomotion, stereotypy and rotations), and consequently immobility decrease until day 4 after reperfusion, compared to control gerbils. Exposure to ELF-MF inhibited development of ischemia-induced motor hyperactivity during the whole period of registration, but significantly in the first 2 days after reperfusion, when the postischemic hyperactivity was most evident. Motor activity of these gerbils was still significantly increased compared to control ones, but only on day 1 after reperfusion. Our results revealed that the applied ELF-MF (50Hz, 0.5mT) decreased motor hyperactivity induced by the 10-min global cerebral ischemia, via modulation of the processes that underlie this behavioural response. [Copyright &y& Elsevier]

Abstract: In addition to morphological changes, global cerebral ischemia leads to functional changes that can be assessed by behavioral examination. The purpose of this study was to investigate the impact of the duration of global cerebral ischemia on the time course of a comprehensive set of motor behaviors in Mongolian gerbils. The common carotid arteries of gerbils were occluded either for 5min, 10min, or 15min. Gerbil motor behavior was recorded in the open field at 24h, 48h, 4 days, 7 days, 14 days, 21 days, and 28 days after reperfusion. Each session lasted for 60min and was composed of six intervals of 10min. Our results revealed that ischemic gerbils quickly develop locomotor and stereotypic hyperactivity, with the expected decrease of resting time. The most evident effect was observed in gerbils submitted to a 15min ischemia, whose locomotor activity returned to nearly normal values after 7 days. In contrast, the duration of global cerebral ischemia had no effects on rearing, clockwise, or counter-clockwise rotation. These findings indicate that exposure to global cerebral ischemia induces changes in locomotion, stereotypy, and resting time. The magnitude and duration of these effects depend on the duration of ischemia. [Copyright &y& Elsevier]