Changes in synaptic efficacy in rat brain slices following extremely low-frequency magnetic field exposure at embryonic and early postnatal age
Changes in synaptic efficacy in rat brain slices following extremely low-frequency magnetic field exposure at embryonic and early postnatal age
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DOI：
10.1016/j.ijdevneu.2013.08.004
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发表时间：
2013-12-01
影响因子：
1.8
通讯作者：
Bardos, Gyorgy
中科院分区：
文献类型：
--
作者：
Balassa, Timea;Varro, Petra;Bardos, Gyorgy
早期的一项研究表明，极低频磁场(ELF-MF)暴露后，成年大鼠脑片的突触效率和癫痫敏感性发生了变化。发育中的胚胎和出生后早期的大脑可能对MF暴露更加敏感。本研究的目的是确定长期的ELF-MF(0.5和3mT，50赫兹)暴露对发育中的大脑突触功能的影响。在大脑发育的两个关键时期，即第二孕周的宫内或从出生后3天开始的新生大鼠，分别进行7天的长期暴露。通过分析细胞外诱发电位，在脑片上检测新皮质和海马区的兴奋性和可塑性。我们证明，两种治疗方法(胎儿0.5mT，新生儿3mT)均可增加海马片的基本兴奋性(以群体峰的幅度衡量)。新皮质脑片似乎对新生儿的治疗反应最好，兴奋性突触后电位的幅度增加。胎儿期ELF-MF暴露可显著抑制双脉冲抑制(PPD)，并显著降低LTP(长时程增强诱导)对大脑皮层的抑制作用，但对海马区无明显影响。另一方面，新生儿治疗对可塑性现象没有显著影响。结果表明，ELF-MF对胎儿期和新生期暴露大鼠脑片的基本神经元功能和突触可塑性均有显著影响。(C)2013年综合业务数字网。爱思唯尔有限公司出版。保留所有权利。
An earlier study demonstrated changes in synaptic efficacy and seizure susceptibility in adult rat brain slices following extremely low-frequency magnetic field (ELF-MF) exposure. The developing embryonic and early postnatal brain may be even more sensitive to MF exposure. The aim of the present study was to determine the effects of a long-term ELF-MF (0.5 and 3 mT, 50 Hz) exposure on synaptic functions in the developing brain. Rats were treated with chronic exposure to MF during two critical periods of brain development, i.e. in utero during the second gestation week or as newborns for 7 days starting 3 days after birth, respectively. Excitability and plasticity of neocortical and hippocampal areas were tested on brain slices by analyzing extracellular evoked field potentials. We demonstrated that the basic excitability of hippocampal slices (measured as amplitude of population spikes) was increased by both types of treatment (fetal 0.5 mT, newborn 3 mT). Neocortical slices seemed to be responsive mostly to the newborn treatment, the amplitude of excitatory postsynaptic potentials was increased. Fetal ELF-MF exposure significantly inhibited the paired-pulse depression (PPD) and there was a significant decrease in the efficacy of LTP (long-term potentiation induction) in neocortex, but not in hippocampus. On the other hand, neonatal treatment had no significant effect on plasticity phenomena. Results demonstrated that ELF-MF has significant effects on basic neuronal functions and synaptic plasticity in brain slice preparations originating from rats exposed either in fetal or in newborn period. (C) 2013 ISDN. Published by Elsevier Ltd. All rights reserved.