Retroactive modulation of spike timing-dependent plasticity by dopamine
Retroactive modulation of spike timing-dependent plasticity by dopamine
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DOI：
10.7554/elife.09685
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发表时间：
2015-10-30
期刊：
影响因子：
7.7
通讯作者：
Paulsen, Ole
中科院分区：
文献类型：
--
作者：
Brzosko, Zuzanna;Schultz, Wolfram;Paulsen, Ole
大多数强化学习模型假设奖励信号在导致奖励的活动之后到达，对可能的潜在细胞机制施加限制。在这里，我们表明，多巴胺，一个积极的强化信号，可以追溯转换海马时间依赖性突触抑制增强。这种作用需要功能性NMDA受体，并且部分通过cAMP/PKA级联的激活来介导。总的来说，我们的研究结果支持这样的想法，即奖励相关的信号可以作用于预先建立的突触资格跟踪，从而将特定的经验与行为上遥远的奖励结果相关联。这一发现确定了解决“远端奖励问题”的生物学合理机制。
Most reinforcement learning models assume that the reward signal arrives after the activity that led to the reward, placing constraints on the possible underlying cellular mechanisms. Here we show that dopamine, a positive reinforcement signal, can retroactively convert hippocampal timing-dependent synaptic depression into potentiation. This effect requires functional NMDA receptors and is mediated in part through the activation of the cAMP/PKA cascade. Collectively, our results support the idea that reward-related signaling can act on a pre-established synaptic eligibility trace, thereby associating specific experiences with behaviorally distant, rewarding outcomes. This finding identifies a biologically plausible mechanism for solving the 'distal reward problem'.