Reinforcement determines the timing dependence of corticostriatal synaptic plasticity in vivo
Reinforcement determines the timing dependence of corticostriatal synaptic plasticity in vivo
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DOI：
10.1038/s41467-017-00394-x
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发表时间：
2017-08-24
影响因子：
16.6
通讯作者：
Reynolds, John N. J.
中科院分区：
文献类型：
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作者：
Fisher, Simon D.;Robertson, Paul B.;Reynolds, John N. J.
皮层和纹状体之间突触的可塑性被认为是学习新动作的关键。然而，对这些突触的spike- time -dependent plasticity （STDP）的研究主要是在脑切片准备中进行的，而没有考虑生理强化信号。这导致了相互矛盾的发现，并阻碍了将神经可塑性与行为联系起来的能力。通过完整大鼠的细胞内纹状体记录，我们发现突触前和突触后的配对活动诱导了强大的Hebbian双向可塑性，依赖于多巴胺和腺苷信号。然而，这种可塑性需要在STDP配对后的2秒内到达奖励条件的感官强化信号，从而揭示了一个与时间相关的强化操作的资格轨迹。通过计算模型和行为测试验证了这些观察结果。我们的研究结果表明，Hebbian皮质纹状体可塑性可以由经典的强化学习机制诱导，并且可能是新行为习得的核心。
Plasticity at synapses between the cortex and striatum is considered critical for learning novel actions. However, investigations of spike-timing-dependent plasticity (STDP) at these synapses have been performed largely in brain slice preparations, without consideration of physiological reinforcement signals. This has led to conflicting findings, and hampered the ability to relate neural plasticity to behavior. Using intracellular striatal recordings in intact rats, we show here that pairing presynaptic and postsynaptic activity induces robust Hebbian bidirectional plasticity, dependent on dopamine and adenosine signaling. Such plasticity, however, requires the arrival of a reward-conditioned sensory reinforcement signal within 2 s of the STDP pairing, thus revealing a timing-dependent eligibility trace on which reinforcement operates. These observations are validated with both computational modeling and behavioral testing. Our results indicate that Hebbian corticostriatal plasticity can be induced by classical reinforcement learning mechanisms, and might be central to the acquisition of novel actions.