Reversal of Long-Term Potentiation-Like Plasticity Processes after Motor Learning Disrupts Skill Retention
Reversal of Long-Term Potentiation-Like Plasticity Processes after Motor Learning Disrupts Skill Retention
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DOI：
10.1523/jneurosci.1399-13.2013
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发表时间：
2013-07-31
影响因子：
5.3
通讯作者：
Celnik, Pablo
中科院分区：
文献类型：
--
作者：
Cantarero, Gabriela;Lloyd, Ashley;Celnik, Pablo
初级运动皮层（M1）中突触连接的可塑性被认为在学习和记忆中起重要作用。人类和动物研究表明，运动学习导致长时程增强（LTP）样可塑性过程，即M1的增强和额外LTP样可塑性的暂时闭塞。此外，LTP所必需的生化过程对某些类型的运动学习和记忆也至关重要。因此，据推测，学习后LTP样可塑性的闭塞，指示了多少LTP用于学习，是必不可少的保留。在这里，我们提供了它在人类中的支持证据。LTP样可塑性的诱导可以使用由短暂的连续θ爆发刺激组成的去电位方案（DePo）来消除。我们使用经颅磁刺激来评估运动学习后在M1上应用DePo是否影响（1）LTP样可塑性的阻断和（2）运动技能学习的保持。我们发现，运动记忆保持的程度与LTP样可塑性的阻断程度成正比。此外，Depo刺激M1，但不是在一个控制网站，逆转闭塞的LTP样可塑性诱导的运动学习和中断技能保留相对于对照组。总而言之，这些结果提供了LTP样可塑性的闭塞和保留之间的联系的证据，这种措施可以用作生物标志物来预测保留。重要的是，试图扭转运动学习后LTP样可塑性的闭塞，其代价是减少运动学习的保留。
Plasticity of synaptic connections in the primary motor cortex (M1) is thought to play an essential role in learning and memory. Human and animal studies have shown that motor learning results in long-term potentiation (LTP)-like plasticity processes, namely potentiation of M1 and a temporary occlusion of additional LTP-like plasticity. Moreover, biochemical processes essential for LTP are also crucial for certain types of motor learning and memory. Thus, it has been speculated that the occlusion of LTP-like plasticity after learning, indicative of how much LTP was used to learn, is essential for retention. Here we provide supporting evidence of it in humans. Induction of LTP-like plasticity can be abolished using a depotentiation protocol (DePo) consisting of brief continuous theta burst stimulation. We used transcranial magnetic stimulation to assess whether application of DePo over M1 after motor learning affected (1) occlusion of LTP-like plasticity and (2) retention of motor skill learning. We found that the magnitude of motor memory retention is proportional to the magnitude of occlusion of LTP-like plasticity. Moreover, DePo stimulation over M1, but not over a control site, reversed the occlusion of LTP-like plasticity induced by motor learning and disrupted skill retention relative to control subjects. Altogether, these results provide evidence of a link between occlusion of LTP-like plasticity and retention and that this measure could be used as a biomarker to predict retention. Importantly, attempts to reverse the occlusion of LTP-like plasticity after motor learning comes with the cost of reducing retention of motor learning.