The Influence of Static Magnetic Fields on Brain tissue

静磁场对脑组织的影响

• 批准号: 6607564
• 负责人: ANDRZEJ WIERASZKO
• 金额: $ 12.68万
• 依托单位: COLLEGE OF STATEN ISLAND
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-12 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6607564
• 关键词: biological transport; calcium flux; cell membrane; evoked potentials; glutamates; hippocampus; laboratory mouse; magnetic field; membrane permeability; protein kinase C; radiobiology

Epidemiological studies have suggested that exposure to electromagnetic fields generated by high-voltage, alternating current (AC) transmission line systems may have adverse effects on the biological systems. Although most of the work on magnetic field effects focused on AC fields, static magnetic fields (SMF) are also present in human environment. They are used in the industry and medicine and number of reports describes the effects of static magnetic fields (SMF) on biological systems. The current in high-voltage DC transmission lines, in opposite to AC lines, do not vary rapidly and is unable to induce current in conducting objects. Therefore, their possible interaction with biological systems would be different than AC fields. The objective of proposed research is to evaluate the influence of SMF on the evoked potentials recorded from mouse hippocampal slices. Hippocampus has been selected since presurgical evaluation of human subjects demonstrated that SMF may trigger epileptic activity in the hippocampus. Additionally, basic hippocampal electrophysiology and morphology is well known and arrangement of cells and fibers creates an environment potentially prone to magnetic fields action. Our preliminary results show that SMF (2-3 mT of intensity) modulate the magnitude of the population spike recorded from mouse hippocampal slices. The initial decline in the potential observed during exposure of the slices to SMF was followed by a recovery/amplification phase, which began after terminating the SMF 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 by antagonists of NMDA receptor. The inhibition of the rising phase of the potential by dantrolene, an inhibitor of intracellular Cat+ channels suggests that intracellular calcium channels participate in the mechanism of SMF action. The SMF effects were limited to orthodromically driven potentials. Our hypothesis is that SMF modulate the movement of Ca2+ ions through cellular membranes. The accumulation of radioactive Ca2+ by slices exposed to SMF will be determined. The influence of SMF on the activity of protein kinase C (PKC) which participates in synaptic mechanisms will be determined. Studies are planned to compare release and uptake of glutamate (a neurotransmitter in a tested pathway) in control and SMF-treated slices. The influence of SMF on individual neurons activity using intracellular recordings are planned. The cell excitability, synaptic efficiency and action potentials recorded from the slices exposed to SMF will be studied. The directions of alternative and future research are delineated.

流行病学研究表明，暴露于高压交流输电线路系统产生的电磁场可能对生物系统产生不利影响。 虽然大多数关于磁场效应的工作集中在交流场，但静磁场（SMF）也存在于人类环境中。 它们用于工业和医学，许多报告描述了静磁场（SMF）对生物系统的影响。 高压直流输电线路中的电流与交流线路相反，不会快速变化，并且无法在导电物体中感应电流。 因此，它们与生物系统的可能相互作用将不同于AC场。 本研究的目的是评价SMF对小鼠海马脑片诱发电位的影响。 选择海马是因为对人类受试者的术前评价表明SMF可能触发海马中的癫痫活动。 此外，基本的海马电生理学和形态学是众所周知的，细胞和纤维的排列创造了一个可能倾向于磁场作用的环境。 我们的初步结果表明，SMF（2-3 mT的强度）调制的大小的群体尖峰记录从小鼠海马切片。 在切片暴露于SMF期间观察到的电位的初始下降之后是恢复/放大阶段，该阶段在终止SMF作用后开始。 在该阶段期间，群体尖峰超过施加磁场之前观察到的幅度。NMDA受体拮抗剂不影响磁场的作用模式。 细胞内Cat+通道抑制剂丹曲林对电位上升相的抑制表明细胞内钙通道参与SMF作用机制。 SMF效应仅限于顺向驱动电位。 我们的假设是，SMF调节Ca 2+离子通过细胞膜的运动。 将测定暴露于SMF的切片的放射性Ca 2+蓄积。将确定SMF对参与突触机制的蛋白激酶C（PKC）活性的影响。 计划进行研究，以比较对照和SMF处理切片中谷氨酸（测试途径中的神经递质）的释放和摄取。 计划使用细胞内记录对单个神经元活动的SMF的影响。 将研究暴露于SMF的切片记录的细胞兴奋性、突触效率和动作电位。 替代和未来的研究方向划定。

项目成果

An increase in cAMP concentration in mouse hippocampal slices exposed to low-frequency and pulsed magnetic fields.

• DOI: 10.1016/j.neulet.2004.05.006
• 发表时间: 2004-08-05
• 期刊: NEUROSCIENCE LETTERS
• 影响因子: 2.5
• 作者: Hogan, MV;Wieraszko, A
• 通讯作者: Wieraszko, A

The actions of a charged melatonin receptor ligand, TMEPI, and an irreversible MT2 receptor agonist, BMNEP, on mouse hippocampal evoked potentials in vitro.

• DOI: 10.1016/j.lfs.2004.06.009
• 发表时间: 2004-11
• 期刊: Life sciences
• 影响因子: 6.1
• 作者: Y. El-Sherif;P. Witt‐Enderby;Pui-Kai Li;Jene Tesoriero;M. V. Hogan;A. Wieraszko