The influence of steady magnetic fields on the mouse hippocampal evoked potentials in vitro

Abstract

Direct current-generated EM fields modulated evoked potentials recorded from hippocampal slices. Both the synaptic efficiency represented by the slope of EPSP and the number of activated pyramidal cells represented by the population spike were modified by EM fields. While the weak EM fields (2-3 mT) exerted a biphasic effect observed as a transient small depression followed by a long-lasting amplification of the potentials, stronger EM fields (8-10 mT) depressed these potentials. This depression could be partially reversed by increasing the strength of the stimulation. It is suggested that EM-induced fluctuations in the intracellular Ca2+ concentration are responsible for the observed effect.

Spontaneous Neocortical Activity and Cognitive Functions: A Neuron-Astroglial Bio-Magnetic and Self-Organized Process

“…The differences between the effects found by different studies might be explained by the different intensities of static magnetic fields used, but it seems that weak static magnetic fields may increase neuronal activity. This conclusion is in agreement with the results found in mouse hippocampal evoked potentials in vitro, which showed that while weak steady magnetic fields (2-3mT) exerted a transient small depression followed by a long-lasting amplification of the potentials, stronger (8-10mT) magnetic fields depressed these potentials (Trabulsi et al, 1996).…”

“…Many experimental works have shown that static magnetic fields can modulate neuronal physiology (Azanza and Calvo, 2000;Azanza and del Moral, 1994;Cavopol et al, 1995;Coots et al, 2004;Liboff, 1979;Rosen, 2003;Trabulsi et al, 1996;Vargas et al, 2006;Wieraszko, 2000;Ye et al, 2004). Some passive membrane properties of neurones are affected by the exposure to weak static magnetic fields, increasing the magnitude of evoked action potentials and excitatory postsynaptic potentials (Ye et al, 2004).…”

Dantrolene modulates the influence of steady magnetic fields on hippocampal evoked potentials in vitro

“…As compared to our previous experiments [Trabulsi et al, 1996], the following modi®cations were introduced to our current methodology: a) the hippocampal slice was always covered with a 1 mm- Fig. 2.…”

“…Currently, the modulation of calcium ion¯ux through the cellular membrane is considered a major factor which could carry the membrane-related DCMF effects into the cell interior [Rosen, 1994] [Bliss and Collindgridge, 1993]. Our previous investigation revealed that DCMF can modulate hippocampal evoked potentials in a dose-dependent fashion [Trabulsi et al, 1996]. The present research was initiated to determine the role of Ca 2 in this phenomenon.…”

Decreased plasma levels of nitric oxide metabolites, angiotensin II, and aldosterone in spontaneously hypertensive rats exposed to 5 mT static magnetic field

“…A variety of SMF induced physiological effects indirectly suggest the involvement of the alternation in Ca 2þ signal pathways in vivo [Okano and Ohkubo, 2001;Gmitrov and Ohkubo, 2002b] and in vitro [Azanza, 1989;Ayrapetyan et al, 1994;Itegin et al, 1995;Rosen, 1996Rosen, , 2003Trabulsi et al, 1996;Flipo et al, 1998;Fanelli et al, 1999;Wieraszko, 2000;Teodori et al, 2002;Liboff et al, 2003]. Nevertheless, a mechanism for the transmission of weak field energy on relevant biological systems, especially the Ca 2þ signal system, is still unknown [Gartzke and Lange, 2002].…”