Stimulus-timing-dependent plasticity of cortical frequency representation.
Stimulus-timing-dependent plasticity of cortical frequency representation.
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DOI：
10.1523/jneurosci.4429-08.2008
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发表时间：
2008-12-10
期刊：
影响因子：
--
通讯作者：
King AJ
中科院分区：
文献类型：
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作者：
Dahmen JC;Hartley DE;King AJ
成年人的皮层回路具有相当大的可塑性，这可以通过修改它们的输入来诱导。神经元反应变化的一种机制是尖峰时间依赖性可塑性（STDP），即突触效能的上调或下调取决于突触前和突触后活动的顺序和时间。感觉刺激与另一感觉刺激或电流注入的重复和异步配对可以以与STDP一致的方式改变视觉和体感神经元的响应特性。为了研究这种可塑性是否也存在于听觉系统中，我们记录了麻醉和清醒的成年雪貂初级听觉皮层的神经元。不同频率的纯音的重复配对引起神经元频率选择性的变化，其表现出类似于STDP的时间特异性。只有对8或12毫秒的刺激起始pixelies是有效的和方向的转变取决于在一对内的音调的顺序。600个刺激对（持续1070 s）足以产生频率调谐的显著变化，并且这种变化持续了几分钟。当条件刺激的频率间隔<0.01倍频程时，观察到的位移幅度最大。此外，显着的变化，发现只有在上皮层。我们的研究结果强调了毫秒级的感觉输入的时间在塑造神经功能的重要性，并强烈建议STDP作为一个相关的机制，在成熟的听觉系统的可塑性。
Adult cortical circuits possess considerable plasticity, which can be induced by modifying their inputs. One mechanism proposed to underlie changes in neuronal responses is spike-timing-dependent plasticity (STDP), an up- or down-regulation of synaptic efficacy contingent upon the order and timing of pre- and postsynaptic activity. The repetitive and asynchronous pairing of a sensory stimulus with either another sensory stimulus or current injection can alter the response properties of visual and somatosensory neurons in a manner consistent with STDP. To examine whether such plasticity also exists in the auditory system, we recorded from neurons in the primary auditory cortex of anesthetized and awake adult ferrets. The repetitive pairing of pure tones of different frequencies induced shifts in neuronal frequency selectivity, which exhibited a temporal specificity akin to STDP. Only pairs with stimulus onset asynchronies of 8 or 12 ms were effective and the direction of the shifts depended upon the order in which the tones within a pair were presented. Six hundred stimulus pairs (lasting ∼70 s) were enough to produce a significant shift in frequency tuning and the changes persisted for several minutes. The magnitude of the observed shifts was largest when the frequency separation of the conditioning stimuli was < ∼1 octave. Moreover, significant shifts were found only in the upper cortical layers. Our findings highlight the importance of millisecond-scale timing of sensory input in shaping neural function and strongly suggest STDP as a relevant mechanism for plasticity in the mature auditory system.