Contribution of axonal orientation to pathway-dependent modulation of excitatory transmission by direct current stimulation in isolated rat hippocampus
Contribution of axonal orientation to pathway-dependent modulation of excitatory transmission by direct current stimulation in isolated rat hippocampus
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DOI：
10.1152/jn.00715.2011
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发表时间：
2012-04-01
影响因子：
2.5
通讯作者：
Rotenberg, Alexander
中科院分区：
文献类型：
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作者：
Kabakov, Anatoli Y.;Muller, Paul A.;Rotenberg, Alexander
Kabakov AY，Muller PA，Pascual-Leone A，Jensen FE，Rotenberg A。轴突取向对直流电刺激所致大鼠海马神经元兴奋性传递通路依赖性调制的贡献。《神经生理学杂志》107：1881-1889,2012。2012年1月4日首次出版；DOI：10.1152/jn.00715.2011。-经颅直流电刺激(TDC)是一种通过头皮电极施加的微弱恒定电流来调节皮质兴奋性的方法。虽然通常用阳极或阴极刺激来描述，但取决于头皮电极靠近感兴趣的皮质区域，神经元结构相对于直流(DC)矢量的方向决定了TDC的效果。为了研究神经通路定位的作用，我们在体外制备的大鼠海马片上研究了DCs介导的神经调节。在恒定的直流电场中，通过记录场兴奋性突触后电位(FEPSP)在CA1神经元顶端和基底部的树突，研究了树突定向在直流电刺激(DC)神经调制效应中的作用。此外，我们通过分别记录刺激相反方向的Schaffer侧支和苔藓纤维轴突产生的CA1和CA3尖端fEPSP来评估轴突取向的贡献。最后，测量非突触兴奋性信号沿逆行刺激的CA1轴突在不同幅度和不同极性下的传播。我们发现，fEPSP和布居峰的调制都依赖于轴突相对于电场矢量的取向。轴突方向决定DC场是兴奋的还是抑制的，树突方向影响DC效应的大小，但不影响总体方向。这些数据表明，如果在恒定电场中由相反方向的轴突兴奋，tDCs可能会相反地影响刺激皮质体积中的神经元。
Kabakov AY, Muller PA, Pascual-Leone A, Jensen FE, Rotenberg A. Contribution of axonal orientation to pathway-dependent modulation of excitatory transmission by direct current stimulation in isolated rat hippocampus. J Neurophysiol 107: 1881-1889, 2012. First published January 4, 2012; doi: 10.1152/jn.00715.2011.-Transcranial direct current stimulation (tDCS) is a method for modulating cortical excitability by weak constant electrical current that is applied through scalp electrodes. Although often described in terms of anodal or cathodal stimulation, depending on which scalp electrode pole is proximal to the cortical region of interest, it is the orientation of neuronal structures relative to the direct current (DC) vector that determines the effect of tDCS. To investigate the contribution of neural pathway orientation, we studied DCS-mediated neuromodulation in an in vitro rat hippocampal slice preparation. We examined the contribution of dendritic orientation to the direct current stimulation (DCS) neuromodulatory effect by recording field excitatory postsynaptic potentials (fEPSPs) in apical and basal dendrites of CA1 neurons within a constant DC field. In addition, we assessed the contribution of axonal orientation by recording CA1 and CA3 apical fEPSPs generated by stimulation of oppositely oriented Schaffer collateral and mossy fiber axons, respectively, during DCS. Finally, nonsynaptic excitatory signal propagation was measured along antidromically stimulated CA1 axons at different DCS amplitudes and polarity. We find that modulation of both the fEPSP and population spike depends on axonal orientation relative to the electric field vector. Axonal orientation determines whether the DC field is excitatory or inhibitory and dendritic orientation affects the magnitude, but not the overall direction, of the DC effect. These data suggest that tDCS may oppositely affect neurons in a stimulated cortical volume if these neurons are excited by oppositely orientated axons in a constant electrical field.