Extremely low frequency magnetic field (50 Hz, 0.5 mT) reduces oxidative stress in the brain of gerbils submitted to global cerebral ischemia.

Magnetic field as ecological factor has influence on all living beings. The aim of this study was to determine if extremely low frequency magnetic field (ELF-MF, 50 Hz, 0.5 mT) affects oxidative stress in the brain of gerbils submitted to 10-min global cerebral ischemia. After occlusion of both carotid arteries, 3-month-old gerbils were continuously exposed to ELF-MF for 7 days. Nitric oxide and superoxide anion production, superoxide dismutase activity and index of lipid peroxidation were examined in the forebrain cortex, striatum and hippocampus on the 7(th) (immediate effect of ELF-MF) and 14(th) day after reperfusion (delayed effect of ELF-MF). Ischemia per se increased oxidative stress in the brain on the 7(th) and 14(th) day after reperfusion. ELF-MF also increased oxidative stress, but to a greater extent than ischemia, only immediately after cessation of exposure. Ischemic gerbils exposed to ELF-MF had increased oxidative stress parameters on the 7(th) day after reperfusion, but to a lesser extent than ischemic or ELF-MF-exposed animals. On the 14(th) day after reperfusion, oxidative stress parameters in the brain of these gerbils were mostly at the control levels. Applied ELF-MF decreases oxidative stress induced by global cerebral ischemia and thereby reduces possible negative consequences which free radical species could have in the brain. The results presented here indicate a beneficial effect of ELF-MF (50 Hz, 0.5 mT) in the model of global cerebral ischemia.

Extremely low frequency magnetic field (50 Hz, 0.5 mT) modifies fitness components and locomotor activity of Drosophila subobscura.

PURPOSE: Extremely low frequency (ELF) magnetic fields are essential ecological factors which may induce changes in many organisms. The aim of this study was to examine the effects in Drosophila subobscura exposed for 48 h to ELF magnetic field (50 Hz, 0.5 mT) at different developmental stages. MATERIALS AND METHODS: Egg-first instar larvae developmental stage of D. subobscura isofemale lines was exposed to ELF magnetic field, and fitness components (developmental time, developmental dynamics, viability and sex ratio) and locomotor activity of three-day-old males and females were monitored. Also, just eclosed D. subobscura isofemale adults were exposed to ELF magnetic field and their locomotor activity was monitored just after. RESULTS: ELF magnetic field shortens developmental time, increases viability and does not affect sex ratio of D. subobscura. No matter which developmental stage is exposed, ELF magnetic field significantly decreases locomotor activity of adult flies, but after exposure of just eclosed adults observed change lasts longer. CONCLUSIONS: Applied ELF magnetic field modifies fitness components and locomotor activity of D. subobscura. Observed effects can be attributed to the influence of magnetic field on different stages of development where the hormonal and nervous systems play important role in the control of examined parameters.

Neuroprotective efficiency of tetanus toxin C fragment in model of global cerebral ischemia in Mongolian gerbils.

The tetanus toxin C (TTC) fragment capacity of being transported in a retrograde way through motoneurons and its nontoxic nature opens the door to a new promising therapeutic strategy for neurodegenerative diseases. In this study, the TTC effect was tested for the first time in animal model of global cerebral ischemia induced by 10-min occlusion of both common carotid arteries. The aim was to evaluate the effect of TTC gene therapy treatment on the development and expression of global cerebral ischemia/reperfusion-induced oxidative stress and motor hyperactivity in Mongolian gerbils. Several oxidative stress and motor behavioral parameters were investigated between 2 h and 14 days after reperfusion. Neuroprotective efficiency of TTC was observed in the forebrain cortex, striatum, hippocampus, and cerebellum at the level of each examined oxidative stress parameter (nitric oxide level, superoxide production, superoxide dismutase activity, and index of lipid peroxidation). Additionally, TTC significantly decreased ischemia-induced motor hyperactivity based on tested parameters (locomotion, stereotypy, and rotations). As judged by biochemical as well as behavioral data, treatment with TTC for the first time showed neuroprotective efficiency by reduction of ischemia-induced oxidative stress and motor hyperactivity and can be a promising strategy for ischemia-induced neuronal damage treatment.

Changes in the expression and current of the Na+/K+ pump in the snail nervous system after exposure to a static magnetic field.

Compelling evidence supports the use of a moderate static magnetic field (SMF) for therapeutic purposes. In order to provide insight into the mechanisms underlying SMF treatment, it is essential to examine the cellular responses elicited by therapeutically applied SMF, especially in the nervous system. The Na(+)/K(+) pump, by creating and maintaining the gradient of Na(+) and K(+) ions across the plasma membrane, regulates the physiological properties of neurons. In this study, we examined the expression of the Na(+)/K(+) pump in the isolated brain-subesophageal ganglion complex of the garden snail Helix pomatia, along with the immunoreactivity and current of the Na(+)/K(+) pump in isolated snail neurons after 15 min exposure to a moderate (10 mT) SMF. Western blot and immunofluorescence analysis revealed that 10 mT SMF did not significantly change the expression of the Na(+)/K(+) pump α-subunit in the snail brain and the neuronal cell body. However, our immunofluorescence data showed that SMF treatment induced a significant increase in the Na(+)/K(+) pump α-subunit expression in the neuronal plasma membrane area. This change in Na(+)/K(+) pump expression was reflected in pump activity as demonstrated by the pump current measurements. Whole-cell patch-clamp recordings from isolated snail neurons revealed that Na(+)/K(+) pump current density was significantly increased after the 10 mT SMF treatment. The SMF-induced increase was different in the two groups of control snail neurons, as defined by the pump current level. The results obtained could represent a physiologically important response of neurons to 10 mT SMF comparable in strength to therapeutic applications.

Age-dependent effects of ELF-MF on oxidative stress in the brain of Mongolian gerbils.

The aim of study was to investigate the effects of extremely low frequency magnetic field (ELF-MF; 50 Hz; 0.1, 0.25 and 0.5 mT) on oxidative stress in the brain of 3- (adult) and 10-month-old (middle-aged) gerbils. Nitric oxide (NO) level, superoxide (O2(-)) production, superoxide dismutase (SOD) activity, and index of lipid peroxidation (ILP) were measured in the forebrain cortex, striatum, hippocampus, and cerebellum immediately and 3 days after cessation of 7-day exposure. In all gerbils, ELF-MF significantly increased oxidative stress in all tested brain regions. This effect was correlated with the value of magnetic induction and was higher in middle-aged gerbils. Three days after cessation of exposure, the values of examined parameters were closer to control levels. In adult gerbils, the effect of ELF-MF of 0.1 mT on NO level, O2(-) production and SOD activity was almost fully disappeared, and ILP was at the control level regardless of the value of magnetic induction. In middle-aged gerbils, the effect of ELF-MF was still present but to a lesser degree than those observed immediately after cessation of exposure. These findings pointed out the ability of ELF-MF to induce age- and magnetic induction-dependent modification of oxidative stress in the brain.

Response of hippocampal neurons and glial cells to alternating magnetic field in gerbils submitted to global cerebral ischemia.

The purpose of this study was to determine whether exposure to an extremely low-frequency magnetic field (ELF-MF, 50 Hz) affects the outcome of postischemic damage in the hippocampus of Mongolian gerbils. After 10-min bilateral carotid occlusion, the gerbils were continuously exposed to ELF-MF (average magnetic induction at the center of the cage was 0.5 mT) for 7 days. The impact of ELF-MF was estimated immediately (the 7th day after reperfusion) and 7 days after cessation of exposure (the 14th day after reperfusion) compared with ischemic gerbils without ELF-MF exposure. Applying stereological methods, histological evaluation of changes in the hippocampus was done for determining its volume, volume densities of degenerating neurons and astrocytes, as well as the number of microglial cells per unit area. ELF-MF per se did not induce any morphological changes, while 10-min global cerebral ischemia led to neuronal death, especially in CA1 region of the hippocampus, as expected. Ischemic gerbils exposed to ELF-MF had significantly a lower degree of cell loss in the examined structure and greater responses of astrocytes and microglial cells than postischemic gerbils without exposure on the seventh day after reperfusion (immediate effect of ELF-MF). Similar response was observed on the 14th day after reperfusion (delayed effect of ELF-MF); however, differences in measured parameters were low and insignificant. Applied ELF-MF has possible neuroprotective function in the hippocampus, as the most sensitive brain structure in the model of global cerebral ischemia, through reduction of neuronal death and activation of astrocytes and microglial cells.

The influence of static magnetic field (50 mT) on development and motor behaviour of Tenebrio (Insecta, Coleoptera).

PURPOSE: There is considerable concern about potential effects associated with exposure to magnetic fields on organisms. Therefore, duration of pupa-adult development and motor behaviour of adults were analyzed in Tenebrio obscursus and T. molitor after exposure to static magnetic field (50 mT). MATERIAL AND METHODS: The experimental groups were: Control (kept 5 m from the magnets), groups which pupae and adults were placed closer to the North pole, or closer to the South pole of magnetic dipole. The pupae were exposed to the magnetic field until the moment of adult eclosion. The pupa-adult development dynamics were recorded daily. Subsequently, behaviour (distance travelled, average speed and immobility) of adults exposed to the magnetic field was monitored in a circular open field arena. RESULTS: Static magnetic field did not affect pupa-adult developmental dynamic of examined Tenebrio species. Exposure to magnetic field did not significantly change motor behaviour of T. obscurus adults. The changes in the motor behaviour of T. molitor induced by static magnetic field were opposite in two experimental groups developed closer to the North pole or closer to the South pole of magnetic dipole. CONCLUSION: Static magnetic field (50 mT) did not affect on pupa-adult development dynamic of two examined Tenebrio species, but modulated their motor behaviour.

Ghrelin effect on nutritional indices, midgut and fat body of Lymantria dispar L. (Lymantriidae).

Ghrelin is a 28-amino acid peptide that has significant effects on appetite and growth in humans and animals. The aim of this study was to examine 4th instar larvae of the pest insect Lymantria dispar L. after ghrelin treatment. Parameters included changes in nutritional indices (efficiency of conversion of ingested food, efficiency of conversion of digested food, approximate digestibility); midgut and fat body mass; total proteases, trypsin and leucine aminopeptidase activities in the midgut; number, height and width of columnar and goblet cells and their nuclei in the midgut epithelium and detection of ghrelin-like immunoreactivity in the midgut tissue. Four subpicomolar injections of ghrelin (0.3pmol) or physiological saline (control) were applied every 24h. The nutritional indices were higher in the ghrelin treated than in the control group. Ghrelin treatment was also associated with elevation of midgut mass, induced digestive enzyme activities, increased fat body mass and morphometric changes in columnar and goblet cells. This is the first report of the presence of ghrelin-like hormone in endocrine cells of an insect midgut. Such information provides additional evidence for application of this relatively simple model system in the future studies of the mechanisms underlying of digestion and energy balance in more complex organisms.

Involvement of Na+/K+ pump in fine modulation of bursting activity of the snail Br neuron by 10 mT static magnetic field.

The spontaneously active Br neuron from the brain-subesophageal ganglion complex of the garden snail Helix pomatia rhythmically generates regular bursts of action potentials with quiescent intervals accompanied by slow oscillations of membrane potential. We examined the involvement of the Na(+)/K(+) pump in modulating its bursting activity by applying a static magnetic field. Whole snail brains and Br neuron were exposed to the 10-mT static magnetic field for 15 min. Biochemical data showed that Na(+)/K(+)-ATPase activity increased almost twofold after exposure of snail brains to the static magnetic field. Similarly, (31)P NMR data revealed a trend of increasing ATP consumption and increase in intracellular pH mediated by the Na(+)/H(+) exchanger in snail brains exposed to the static magnetic field. Importantly, current clamp recordings from the Br neuron confirmed the increase in activity of the Na(+)/K(+) pump after exposure to the static magnetic field, as the magnitude of ouabain's effect measured on the membrane resting potential, action potential, and interspike interval duration was higher in neurons exposed to the magnetic field. Metabolic pathways through which the magnetic field influenced the Na(+)/K(+) pump could involve phosphorylation and dephosphorylation, as blocking these processes abolished the effect of the static magnetic field.

Temporal patterns of extremely low frequency magnetic field-induced motor behavior changes in Mongolian gerbils of different age.

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.

Extremely low frequency magnetic field induced changes in motor behaviour of gerbils submitted to global cerebral ischemia.

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.

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.

Changes of behavioral parameters during long-term food restriction in middle-aged Wistar rats.

Food restriction (FR) has a beneficial effect on aging process and exerts a significant effect on the responses of rodents to standard behavioral tasks. The aim of this study was to assess the cumulative influence of FR on the behavioral and biochemical parameters in Wistar rats. Six-month-old rats were subjected to restrictive feeding (50% of the daily food intake, every-other-day feeding regimen) for one month or for six months until ages of 7 and 12months, respectively. We examined the habituation of exploratory movement, amphetamine (AMPH)-induced motor activity, as well as changes in serum corticosterone (CORT) and glucose levels. The results obtained from FR animals were compared with ad libitum (AL)-fed age-matched control rats. Habituation of motor activity was only affected by six months of restrictive feeding. The sensitization of the motor response to AMPH that was observed in animals exposed to FR for one month was not observed in animals that were exposed to the same feeding regimen for six months. Serum CORT was increased and serum glucose was decreased in both FR groups. These results clearly show that despite the similarity of the biochemical changes that were induced by one and six months of FR, the nature of the changes in motor activities in these two groups of animals during habituation and after AMPH treatment was different. Our findings indicate that long-term FR has complex behavioral consequences that need to be carefully evaluated with respect to animal age, duration of FR and severity of the diet.

MK-801 effect on regional cerebral oxidative stress rate induced by different duration of global ischemia in gerbils.

We investigated MK-801 effect on ischemia-induced oxidative stress-the most important factor that exacerbates brain damage by reperfusion. The common carotid arteries of gerbils were occluded for 5, 10, or 15 min. Immediately after the occlusion, MK-801 (3 mg/kg i.p.) or saline were given in normothermic conditions. The MK-801 effects were followed in vivo by monitoring the neurological status of animals and at the intracellular level by standard biochemical assays. We investigated nitric oxide levels, superoxide production, superoxide dismutase activity, index of lipid peroxidation (ILP), and reduced glutathione content in hippocampus, striatum, forebrain cortex, and cerebellum. The measurements took place at different times (1, 2, 4, 7, 14, and 28 days) after reperfusion. Increased duration of cerebral ischemia resulted in a progressive induction of oxidative stress. Our results revealed pattern of dynamic changes in each oxidative stress parameter level which corresponded with ischemia duration in all tested brain structures. Most sensitive oxidative stress parameters were ILP and superoxide production. Our study confirmed spatial distribution of ischemia-induced oxidative stress. Tested brain structures showed different sensitivity to each oxidative stress parameter. As judged by biochemical and neurological data, applied MK-801 showed neuroprotective efficiency by reduction of ischemia-induced oxidative stress in brain.

Repeated exposure to low-level extremely low frequency-modulated microwaves affects cortex-hypothalamus interplay in freely moving rats: EEG study.

PURPOSE: To compare the effects of repeated exposure to extremely low frequency-modulated microwaves (ELF-MW) on cortical and hypothalamic electroencephalograms (EEG). MATERIALS AND METHODS: In 10 freely moving rats with carbon electrodes implanted into the cortex and dorsomedial hypothalamus, averaged frequency spectra (0.5-30 Hz) of the EEG were studied for five consecutive days either under sham exposures (five rats) or under mixed sham/MW-exposures (five rats). The rats were exposed to ELF-MW (915 MHz, 20-ms pulse duration, approximately 0.3 mW/cm(2), 4 Hz) intermittently (1-min 'On', 1-min 'Off') for 10 min (specific absorption rate, SAR, approximately 0.7 mW/g on average) several times per day, with 10-min pre- and post-exposure periods. RESULTS: In baseline EEG, the activities of 3.2-6.0 Hz and 17.8-30.5 Hz dominated in the cortex and of 6.0-17.8 Hz in the hypothalamus. This cortical-hypothalamic imbalance was relatively stable at sham-exposures and insensitive to ELF-MW in all frequency ranges but one. ELF-MW increased the beta(2) (17.8-30.5 Hz) level in the hypothalamus to a greater extent than in the cortex, causing significant diminishing of the initial EEG bias between them. Moreover, a cumulative phenomenon under repeated exposures to ELF-MW was revealed. CONCLUSIONS: These results are in line with evidence that repeated low-level exposure to ELF-MW affects brain functioning and provide an additional approach when analysing underlying mechanisms.

Effect of continuous exposure to alternating magnetic field (50 Hz, 0.5 mT) on serotonin and dopamine receptors activity in rat brain.

External magnetic fields (MFs) have the ability to modify motor activity of animals, complex type of behaviour connected with dopaminergic and serotonergic neurotransmissions in the brain. Thus, the purpose of this study was to examine MF-induced changes in the activity of serotonin 5-HT(2A) receptors in the prefrontal cortex, as well as dopamine D(1) and D(2) receptors in the striatum of adult Wistar rats, considering their involvement in motor behavior regulation. Experimental animals were continuously exposed to extremely low frequency MF (ELF-MF, 50 Hz, 0.5 mT) for 1, 3, and 7 days. Subsequently, binding properties (K(d) and B(max)) of receptors were determined by in vitro radioligand receptor binding assays. It was shown that the affinity of serotonin 5-HT(2A) receptors decreased and their density increased in the prefrontal cortex of rats after ELF-MF exposure. Regarding affinity, this effect was duration-dependent and most prominent after 7-day of ELF-MF exposure. In contrast to serotonin 5-HT(2A) receptors in the prefrontal cortex, ELF-MF had no significant effect on the affinity and density of dopamine D(1) and D(2) receptors in the striatum. We can conclude that continuous exposure to ELF-MF up to 7 days affects cortical serotonergic neurotransmission, whereby intensity of these changes depends on ELF-MF exposure duration.

Temporal patterns of motor behavioural improvements by MK-801 in Mongolian gerbils submitted to different duration of global cerebral ischemia.

The purpose of this study was to investigate the temporal pattern of NMDA receptors antagonist-MK-801 on motor behaviour parameters in gerbils submitted to different duration of global cerebral ischemia. The common carotid arteries of gerbils were occluded for 5, 10 or 15min. Gerbils were given MK-801 (3mg/kg i.p.) or saline immediately after the occlusion in normothermic conditions prior to testing. Motor activity was registered 1, 2, 4, 7, 14, 21 and 28 days after reperfusion during 60min by open field test. At the same time, the effect of NMDA receptor blockade was followed in vivo by monitoring the neurological status of whole animals or at the cellular level by standard light and confocal microscopy on brain slices. Post-ischemic gerbils quickly developed hypermotor response with the most intensity in animals submitted to 15min ischemia. MK-801 administrated immediately after ischemia significantly decreased this hyperactivity. In all ischemic-treated animals, behavioural suppression by MK-801 was observed already 1 day after occlusion and was lasting as far as observed ischemia-dependent hypermotor responses. Beneficial effect of MK-801 was also confirmed by morphological and neurological status data. These findings suggest that sustained ischemia-induced hyperactivity is related to abnormalities in NMDA glutamatergic function, as well as its manifestation could be completely abolished by NMDA receptor blockade immediately after ischemic insult.

Time course of motor behavior changes in Mongolian gerbils submitted to different durations of cerebral ischemia.

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 5 min, 10 min, or 15 min. Gerbil motor behavior was recorded in the open field at 24 h, 48 h, 4 days, 7 days, 14 days, 21 days, and 28 days after reperfusion. Each session lasted for 60 min and was composed of six intervals of 10 min. 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 15 min 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.

Different effects of chronic exposure to ELF magnetic field on spontaneous and amphetamine-induced locomotor and stereotypic activities in rats.

The effects of chronic (7 days) exposure to an extremely low frequency magnetic field (ELF-MF, 50 Hz, 0.5 mT) on spontaneous and amphetamine-induced (1.5mg/kg, i.p.) locomotor and stereotypic activities in adult rats were examined by open field test for 2h on exposure days 1, 3, and 7. After 1 day of exposure to ELF-MF, the spontaneous locomotor activity was increased clearly at the first hour of observation and significantly at the second one as compared to the corresponding values in other series with ELF-MF and sham-exposed animals. After 7 days of exposure to ELF-MF, an amphetamine enhancing effect on the locomotor activity was significantly reduced at the second hour of observation as compared to that in 1-day- and sham-exposed rats treated with amphetamine. In contrast to the locomotor activity, the amphetamine-induced stereotypic behaviour in 7-day pre-exposed rats was significantly reduced at the first hour versus sham-exposed rats. While at the second hour of observation this effect was significant as compared to 1- and 3-day exposed animals (but not sham-exposed rats). Our results indicate that an extremely low frequency magnetic field is able to affect differently two types of behaviour, which are dependent on both the time course of exposure and the imbalance in the brain mediatory systems.

The effects of exposure to extremely low-frequency magnetic field and amphetamine on the reduced glutathione in the brain.

Continuous exposure to extremely low-frequency magnetic field (ELF-MF, 50 Hz, 0.5 mT) alone and combined with D-amphetamine (1.5 mg/kg) affected the reduced glutathione content in brain regions of rats. Compared to sham-exposed rats, the glutathione content in the forebrain cortex of the ELF-MF-exposed rats decreased (P < 0.001), but this reverted after giving amphetamine upon ELF-MF exposure. In this group, the glutathione content was increased in the brain stem and cerebellum (P < 0.05 compared to the sham-exposed, ELM-MF-exposed, and amphetamine-treated groups). It is suggested that biogenic monoamines are involved in the reduced glutathione changes observed. The changes are not uniform in the brain regions examined.