Exposure to AC and DC magnetic fields induces changes in 5‐HT_1B receptor binding parameters in rat brain membranes

Abstract

The binding properties of the G-protein coupled receptor (GPCR) serotonin 5-HT1B receptor were studied under exposure to AC (50 and 400 Hz) and DC magnetic fields (MF) in rat brain membranes. This was an attempt at replicating the positive findings of Massot et al. In saturation experiments using [3H]5-HT, 1-h exposures at 1.1 mT(rms) 50 Hz caused statistically significant increases in both the K(D) and B(max) binding parameters, from 1.74 +/- 0.3 to 4.51 +/- 0.86 nM and from 1428 +/- 205 to 2137 +/- 399 CPM, respectively, in good agreement with previous results. Exposure of the membranes at 400 Hz 0.675 mT(rms) did not elicit a larger increase in K(D) in spite of a much larger induced current density. DC fields (1.1 and 11 mT) had a lesser effect compared to AC fields at low values of K(Dsham), but decreased the affinity at higher values of K(Dsham). Modeling of the receptor-ligand-G protein interactions using the extended ternary complex model yielded good fits for all our data and that of Massot et al., showing that the AC field may act by decreasing the ability of the G-protein to alter the ligand-receptor affinity. The hypothesis is that the bipolar nature of the AC field explains the different nature of the effects observed with AC and DC exposures. These findings constitute one of the few documented pieces of evidence for cell-free effects of DC and extremely low frequency (ELF) AC MFs in the mT range.

Extremely Low Frequency Magnetic Field (50 Hz, 0.5 mT) Reduces Oxidative Stress in the Brain of Gerbils Submitted to Global Cerebral Ischemia

“…Its influence on ionic currents and pumps [34]–[36], neurotransmission [37]–[43] and behaviour [42], [44]–[52] has been well documented. This influence could be achieved through interaction of ELF-MF with chemical bonds between adjacent atoms leading to change in reaction between biomolecules [53] and disruption of biomembrane changing structure of its protein molecules [54].…”

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

“…Our results are consistent with these data and confi rm once again the ability of ELF-MF to modulate diff erent steps of synaptic transmission in the brain structures involved in control of motor behavior. Th e infl uence of ELF-MF on the processes of synthesis, storage, release and inactivation of diff erent neurotransmitters such as DA, ACh, Glu and 5-HT, as well as activity of their receptors in the brain was already demonstrated (Lai and Carino 1999, Lewy et al 2003, Siero c´ et al 2004, Zhang et al 2005, Espinosa et al 2006, Manikonda et al 2007, Shin et al 2007, Jana c´ et al 2009, Ravera et al 2010). However, it is possible that these eff ects are still not unique and there are some peculiarities in the sensitivity of diff erent brain structures to the external magnetic fi elds, including the nucleus accumbens (NAc), dorsal striatum and brainstem/basal forebrain region which are responsible for a control of locomotion, stereotypy and immobility, respectively (Sharp et al 1987, Kuczenski et al 1997, Klemm 2001.…”

Short- and long-term exposure to alternating magnetic field (50 Hz, 0.5 mT) affects rat pituitary ACTH cells: Stereological study

“…Being a tracer of technological development in a modern world, alternating magnetic field of extremely low frequency (ELF‐MF, <300 Hz) is a physical factor with a growing presence. There is plethora literature data confirming its influence on individual cells, tissues, and organisms in manner of changing ion currents (Huang et al, ; Manikonda et al, ), neurotransmission (Sieroń et al, ; Espinoza et al, ; Janać et al, ), and behavior (Choleris et al, ; Del Seppia et al, ; Shin et al, ). Also, some studies show correlation of some malignant diseases and exposure to ELF‐MF (Johansen, ).…”