Plasticity of the synaptic modification range
Plasticity of the synaptic modification range
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DOI：
10.1152/jn.00164.2007
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发表时间：
2007-12-01
影响因子：
2.5
通讯作者：
Dunaevsky, A.
中科院分区：
文献类型：
--
作者：
Rioult-Pedotti, M. -S.;Donoghue, J. P.;Dunaevsky, A.
依赖活动的突触可塑性可能为学习和记忆提供一种机制。在5天的运动技能学习后，在固定的突触修改范围内得到加强的皮质突触反应被驱动到接近其范围的顶端，仅留下有限的空间用于额外的突触加强。如果突触强化是获得新技能的必要步骤，那么长时程增强(LTP)的接近饱和应该会阻碍进一步的学习，或者LTP机制应该在单任务学习后恢复。在这里，我们表明，即使在训练停止很长时间后，最初的学习诱导的突触增强仍然持续，突触修改范围向上移动。这种射程变化将增加的基线突触效率重新置于其工作范围的中间，允许学习前水平的LTP和长期抑郁。持续性突触强化可能是运动皮质长期滞留的底物，而突触修饰范围的改变确保了新突触强化的可用性。
Activity-dependent synaptic plasticity is likely to provide a mechanism for learning and memory. Cortical synaptic responses that are strengthened within a fixed synaptic modification range after 5 days of motor skill learning are driven near the top of their range, leaving only limited room for additional synaptic strengthening. If synaptic strengthening is a requisite step for acquiring new skills, near saturation of long-term potentiation (LTP) should impede further learning or the LTP mechanism should recover after single-task learning. Here we show that the initial learning- induced synaptic enhancement is sustained even long after training has been discontinued and that the synaptic modification range shifts upward. This range shift places increased baseline synaptic efficacy back within the middle of its operating range, allowing prelearning levels of LTP and long-term depression. Persistent synaptic strengthening might be a substrate for long-term retention in motor cortex, whereas the shift in synaptic modification range ensures the availability for new synaptic strengthening.