Dantrolene modulates the influence of steady magnetic fields on hippocampal evoked potentials in vitro.
Direct current-generated magnetic fields (2-3 mT, 20-min exposure) exerted biphasic effects on the population spike recorded from hippocampal slices. The initial decrease in the potential, observed during exposure of the slices to magnetic fields was followed by a recovery/amplification phase, which began after terminating the magnetic field action. During that phase the population spike exceeded the amplitude observed before application of the magnetic fields. The pattern of magnetic fields influence was not affected either by (+)-5-methyl-10,11-dihydro-5H-dibenzo (a,d) cyclohepten-5, 10-imine maleate (MK801), or by D,L,-2amino-5phosphonovalerate (APV), a noncompetitive and competitive NMDA receptor antagonist, respectively. The rising phase of the potential, however, was eliminated by dantrolene, an inhibitor of intracellular Ca(2 +) channels. This suggests that intracellular calcium channels participate in the mechanism of the influence of the direct current magnetic fields on the function of the hippocampal tissue.
Wieraszko
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CSI/IBR Center for Developmental Neuroscience and Developmental Disabilities, and Department of Biology, College of Staten Island/CUNY, Staten Island, New York 10314, USA. wieraszko@postbox.csi.cuny.edu
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000528:radiation effects; D003620:Dantrolene / Q000494:pharmacology*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D055590:Electromagnetic Phenomena; D005071:Evoked Potentials / Q000187:drug effects / Q000528:radiation effects*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000528:radiation effects*; D008280:Magnetics; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009125:Muscle Relaxants, Central / Q000494:pharmacology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000528:radiation effects
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D018691:Excitatory Amino Acid Antagonists; D009125:Muscle Relaxants, Central; D016194:Receptors, N-Methyl-D-Aspartate; D016291:Dizocilpine Maleate; D015763:2-Amino-5-phosphonovalerate; D003620:Dantrolene