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Magnetic field effects on exploration behaviour of rodents
Štefanská, Lucie ; Němec, Pavel (advisor) ; Sedláček, František (referee)
Magnetoreception, i.e., the ability of animals to detect magnetic field parameters, has been described in a number of phylogeneticaly distant species, including mammals. Animals that regularly undertake long migrations, as well as non-migratory species, are able to make use of directional information derived from the Earth magnetic field. Recently, this ability has been documented in laboratory mice from the C57BL/6J strain, which were used as the model organism also in our study. The aim of this thesis was to analyze the locomotory activity and behavioral parameters in mice exposed to various experimentally manipulated magnetic fields in an open field test (OFT). Overall, the effect of experimental magnetic fields on activity level and behaviors of C57BL/6J mice during OFT exploration was rather weak. Nevertheless, a detailed analysis revealed that magnetic fields influenced the angular velocity of mice in the first 20 minutes of the OFT and the following behaviors: grooming, digging, and nose-to-wall contacts. Different parameters of magnetic fields affected different behaviours in a specific manner. Changes of behavior in time were most visibly affected. These results remain open to interpretation, however, it seems that the experimentally manipulated magnetic fields might represent stimulus...
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Effect of weak magnetic fields on animal physiology and behavior
Štefanská, Lucie ; Němec, Pavel (advisor) ; Vácha, Martin (referee)
Weak magnetic fields from different sources constitute a part of the environment, in which animals live. Therefore one can suppose their effect on animal behavior and physiology, including ontogenetic development. The geomagnetic field is ubiquitous and life on Earth has been accompanied by it from the very beginning. Therefore it seems not to be surprising, that diverse animals are able to detect the geomagnetic field and use it as a cue for orientation and navigation, the ability referred to as magnetoreception. Despite being phylogenetically widespread, the transduction mechanisms and the neural basis of magnetoreception and magnetic orientation remain largely unclear. Three major hypotheses are gaining experimental support: mechanisms based on electromagnetic induction, biogenic magnetite and radical pair reactions. In addition to magnetoreception, various other effects of week magnetic fields on organisms have been reported. Most notably, irregular changes of the geomagnetic field (especially geomagnetic storms) and alternating artificial magnetic fields, which have appeared in the environment due to electrification, are considered to have an effect on locomotor activity, learning and memory, nociception, melatonin synthesis and circadian rhythms, cardiovascular system, gene expression and...
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