Distinct Subthreshold Mechanisms Underlying Rate-Coding Principles in Primate Auditory Cortex.
Distinct Subthreshold Mechanisms Underlying Rate-Coding Principles in Primate Auditory Cortex.
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DOI：
10.1016/j.neuron.2016.07.004
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发表时间：
2016-08-17
期刊：
影响因子：
16.2
通讯作者：
Wang X
中科院分区：
文献类型：
--
作者：
Gao L;Kostlan K;Wang Y;Wang X
在猴子的听觉和体感皮层中编码时变信号的一个关键计算原理是两个不同神经元群体的速率编码的对手模型。然而，引起这种计算的阈下机制还没有被揭示。由于速率编码神经元仅在清醒状态下观察到，因此探索其潜在的细胞机制尤其具有挑战性。使用一种新的细胞内记录技术，我们在清醒的绒猴开发，我们发现，在听觉皮层的两种类型的速率编码神经元表现出不同的阈下反应。正单调神经元（随着刺激重复频率的增加而单调增加放电率）在高重复频率下显示持续去极化，而负单调神经元（相反趋势）在高重复频率下显示超极化，但在低重复频率下显示持续去极化。兴奋性和抑制性阈下事件的组合允许皮层通过这两个对立的神经元群体来表示随时间变化的信号。
A key computational principle for encoding time-varying signals in auditory and somatosensory cortices of monkeys is the opponent model of rate-coding by two distinct populations of neurons. However, the subthreshold mechanisms that give rise to this computation have not been revealed. Because the rate-coding neurons are only observed in awake conditions, it is especially challenging to probe their underlying cellular mechanisms. Using a novel intracellular recording technique that we developed in awake marmosets, we found that the two types of rate-coding neurons in auditory cortex exhibited distinct subthreshold responses. While the positive-monotonic neurons (monotonically increasing firing rate with increasing stimulus repetition frequency) displayed sustained depolarization at high repetition frequency, the negative-monotonic neurons (opposite trend) instead exhibited hyperpolarization at high repetition frequency but sustained depolarization at low repetition frequency. The combination of excitatory and inhibitory subthreshold events allows the cortex to represent time-varying signals through these two opponent neuronal populations.