Sensitivity of coherent oscillations in rat hippocampus to AC electric fields
Sensitivity of coherent oscillations in rat hippocampus to AC electric fields
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DOI：
10.1113/jphysiol.2007.137711
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发表时间：
2007-09-01
影响因子：
5.5
通讯作者：
Jefferys, John G. R.
中科院分区：
文献类型：
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作者：
Deans, Jacqueline K.;Powell, Andrew D.;Jefferys, John G. R.
脑组织对弱细胞外电场的敏感性在评估极低频（ELF）场的潜在公共卫生风险以及内源性场在脑功能中的潜在作用方面非常重要。在这里，我们确定的膜电位和相干网络振荡上施加的电场的效果。外加直流电场使CA 3锥体细胞胞体的跨膜电位每V m（-1）改变0.18 mV。交流正弦电场对跨膜电位的影响较小：灵敏度随频率呈指数衰减函数下降。在50和60 Hz时，它类似于DC场的0.4。= 6 V m（-1）p-p（2.1 V m（-1）r.m.s.）将功率谱中的伽马峰移动到所施加的场频率或次谐波的中心。在不同的阈值下，对锥体细胞放电时间的统计学显著影响出现在振荡中：在50 Hz时，I V m（-1）p-p（354 mV m-1 r.m.s.）在71%的切片中有统计学显著性影响，0.5 V m（-1）p-p（177 mV m（-1）r.m.s.）20%。这些阈值字段符合当前的环境准则。它们对应于70 AV的躯体电位的变化，低于神经元的膜电位噪声水平，表明神经元网络的涌现特性可能比单个神经元中的可测量效应更敏感。
The sensitivity of brain tissue to weak extracellular electric fields is important in assessing potential public health risks of extremely low frequency (ELF) fields, and potential roles of endogenous fields in brain function. Here we determine the effect of applied electric fields on membrane potentials and coherent network oscillations. Applied DC electric fields change transmembrane potentials in CA3 pyramidal cell somata by 0.18 mV per V m(-1) applied. AC sinusoidal electric fields have smaller effects on transmembrane potentials: sensitivity drops as an exponential decay function of frequency. At 50 and 60 Hz it is similar to 0.4 that for DC fields. Effects of fields of = 6 V m(-1) p-p (2.1 V m(-1) r.m.s.) shifted the gamma peak in the power spectrum to centre on the applied field frequency or a subharmonic. Statistically significant effects on the timing of pyramidal cell firing within the oscillation appeared at distinct thresholds: at 50 Hz, I V m(-1) p-p (354 mV m-1 r.m.s.) had statistically significant effects in 71% of slices, and 0.5 V m(-1) p-p (177 mV m(-1) r.m.s.) in 20%. These threshold fields are consistent with current environmental guidelines. They correspond to changes in somatic potential of 70 AV, below membrane potential noise levels for neurons, demonstrating the emergent properties of neuronal networks can be more sensitive than measurable effects in single neurons.