Swayne Orlando B C, Teo James T H, Greenwood Richard J, Rothwell John C
Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College, London, UK.
Clin Neurophysiol. 2009 Aug;120(8):1610-5. doi: 10.1016/j.clinph.2009.06.013. Epub 2009 Jul 28.
Intermittent theta burst stimulation (iTBS) is increasingly widely used as a means of facilitating corticospinal excitability in the human primary motor cortex. This form of facilitatory plasticity within the stimulated cortex may occur by induction of long term potentiation (LTP). In animal models, agonists of nicotinic acetylcholine receptors have been shown to modulate or induce LTP; we thus sought to test whether nicotine may modulate the effects of iTBS on corticospinal excitability in humans.
A double-blind placebo-controlled cross-over design study was conducted with 10 healthy subjects. iTBS was delivered 60min after subjects took either 4mg nicotine or placebo lozenges, and motor-evoked potentials (MEPs) were then recorded for 40min after the end of stimulation.
In the placebo arm, iTBS produced an increase in the amplitudes of MEPs which lasted for 5min. In the nicotine arm, iTBS produced a more pronounced facilitation of MEPs that was still present at 40min. In a control experiment, nicotine alone had no effect on MEP amplitudes when given in the absence of iTBS.
These data indicate that the effects of iTBS can be enhanced and prolonged by nicotine.
These results are consistent with animal models demonstrating nicotinic modulation of facilitatory plasticity, and will be of interest to investigators seeking to enhance artificially induced changes in cortical excitability.
间歇性θ波爆发刺激（iTBS）作为一种增强人类初级运动皮层皮质脊髓兴奋性的手段，应用越来越广泛。受刺激皮层内这种形式的易化可塑性可能是通过诱导长时程增强（LTP）产生的。在动物模型中，烟碱型乙酰胆碱受体激动剂已被证明可调节或诱导LTP；因此，我们试图测试尼古丁是否能调节iTBS对人类皮质脊髓兴奋性的影响。
对10名健康受试者进行了一项双盲安慰剂对照交叉设计研究。在受试者服用4mg尼古丁或安慰剂含片60分钟后给予iTBS，然后在刺激结束后记录40分钟的运动诱发电位（MEP）。
在安慰剂组中，iTBS使MEP的波幅增加，持续5分钟。在尼古丁组中，iTBS对MEP产生了更明显且在40分钟时仍存在的易化作用。在对照实验中，在没有iTBS的情况下单独给予尼古丁对MEP波幅没有影响。
这些数据表明尼古丁可增强并延长iTBS的作用。
这些结果与动物模型中烟碱对易化可塑性的调节作用一致，对于寻求增强人工诱导的皮层兴奋性变化的研究人员具有参考价值。
