Direct current stimulation boosts hebbian plasticity in vitro
Direct current stimulation boosts hebbian plasticity in vitro
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DOI：
10.1016/j.brs.2019.10.014
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发表时间：
2020-03-01
影响因子：
7.7
通讯作者：
Parra, Lucas C.
中科院分区：
文献类型：
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作者：
Kronberg, Greg;Rahman, Asif;Parra, Lucas C.
背景：有证据表明经颅直流电刺激（tDCS）可以提高学习成绩。可以说，这种效应与长期增强（LTP）有关，但确切的生物物理机制尚不清楚。假设：我们提出直流电刺激（DCS）在持续的内源性突触活动中引起突触后膜电位的微小变化。突触后神经元的电压动态变化通过内源性电压依赖的Hebbian可塑性机制改变了突触强度。这一假说预测DCS应该表现出Hebbian特性，即通路特异性和关联性。方法：采用生物物理计算模型研究DCS在大鼠海马CAl区诱导LTP过程中的作用。结果：DCS增强LTP，但仅发生在可塑性突触，证实DCS尊重Hebbian通路特异性。当不同的突触通路合作产生LTP时，DCS加强了这种合作，增强了Hebbian联想性。进一步的切片实验和计算机模拟支持一种模型，即突触后锥体神经元的极化通过内源性Hebbian机制驱动这些可塑性效应。该模型能够通过捕捉感应电场、神经元形态和内源性神经活动之间复杂的相互作用来调和几个实验结果。结论：tDCS可促进联想学习。我们建议临床tDCS应应用于诱导Hebbian可塑性的任务中，以利用这一现象，并且通过它们与内源性可塑性机制的相互作用，效果应该是特定于任务的。结合大脑状态和可塑性机制的模型可能有助于改善tDCS结果的预测。(C) 2019 Elsevier Inc.
Background: There is evidence that transcranial direct current stimulation (tDCS) can improve learning performance. Arguably, this effect is related to long term potentiation (LTP), but the precise biophysical mechanisms remain unknown.Hypothesis: We propose that direct current stimulation (DCS) causes small changes in postsynaptic membrane potential during ongoing endogenous synaptic activity. The altered voltage dynamics in the postsynaptic neuron then modify synaptic strength via the machinery of endogenous voltage-dependent Hebbian plasticity. This hypothesis predicts that DCS should exhibit Hebbian properties, namely pathway specificity and associativity.Methods: We studied the effects of DCS applied during the induction of LTP in the CAl region of rat hippocampal slices and using a biophysical computational model.Results: DCS enhanced LTP, but only at synapses that were undergoing plasticity, confirming that DCS respects Hebbian pathway specificity. When different synaptic pathways cooperated to produce LTP, DCS enhanced this cooperation, boosting Hebbian associativity. Further slice experiments and computer simulations support a model where polarization of postsynaptic pyramidal neurons drives these plasticity effects through endogenous Hebbian mechanisms. The model is able to reconcile several experimental results by capturing the complex interaction between the induced electric field, neuron morphology, and endogenous neural activity.Conclusions: These results suggest that tDCS can enhance associative learning. We propose that clinical tDCS should be applied during tasks that induce Hebbian plasticity to harness this phenomenon, and that the effects should be task specific through their interaction with endogenous plasticity mechanisms. Models that incorporate brain state and plasticity mechanisms may help to improve prediction of tDCS outcomes. (C) 2019 Elsevier Inc.