Spike-timing precision underlies the coding efficiency of auditory receptor neurons
Spike-timing precision underlies the coding efficiency of auditory receptor neurons
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DOI：
10.1152/jn.00891.2005
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发表时间：
2006-04-01
影响因子：
2.5
通讯作者：
Samengo, I
中科院分区：
文献类型：
--
作者：
Rokem, A;Watzl, S;Samengo, I
感官系统必须快速可靠地转换传入的信号，以便动物能够在其环境中成功地采取行动。然而，即使在受体神经元的水平上，感觉编码过程的功能方面也尚未完全理解。具体来说，这涉及的问题是刺激特征和神经反应特征如何导致感官信息的有效传输。为了解决这个问题，我们记录和分析了蝗虫听觉感受器的尖峰列车，同时系统地改变刺激统计。刺激的变化深刻地影响了神经编码的效率。这种影响在很大程度上是由于存在的特定刺激功能，触发非常精确的尖峰，其审判到审判的时间变异性低至0.15毫秒，一个数量级短于典型的刺激时间尺度。精确的尖峰脉冲降低了尖峰脉冲序列的噪声熵，从而提高了信息传输的速率。与此相反，总尖峰序列熵，量化的各种不同的尖峰序列模式，几乎没有改变时，刺激条件的改变，只要神经放电率保持不变。这一发现表明，以高信息速率传输的刺激分布并没有引起额外的反应模式，而是在其神经表征中显示出异常的时间精度。导致最高信息率和最小尖峰时间抖动的声学刺激具有持续2-3 ms的明显声压偏转。这些上行让人想起自然蚱蜢通信信号中发现的显着结构，这表明精确的尖峰选择性地编码特别重要的方面自然刺激环境。
Sensory systems must translate incoming signals quickly and reliably so that an animal can act successfully in its environment. Even at the level of receptor neurons, however, functional aspects of the sensory encoding process are not yet fully understood. Specifically, this concerns the question how stimulus features and neural response characteristics lead to an efficient transmission of sensory information. To address this issue, we have recorded and analyzed spike trains from grasshopper auditory receptors, while systematically varying the stimulus statistics. The stimulus variations profoundly influenced the efficiency of neural encoding. This influence was largely attributable to the presence of specific stimulus features that triggered remarkably precise spikes whose trial-to-trial timing variability was as low as 0.15 ms-one order of magnitude shorter than typical stimulus time scales. Precise spikes decreased the noise entropy of the spike trains, thereby increasing the rate of information transmission. In contrast, the total spike train entropy, which quantifies the variety of different spike train patterns, hardly changed when stimulus conditions were altered, as long as the neural firing rate remained the same. This finding shows that stimulus distributions that were transmitted with high information rates did not invoke additional response patterns, but instead displayed exceptional temporal precision in their neural representation. The acoustic stimuli that led to the highest information rates and smallest spike-time jitter feature pronounced sound-pressure deflections lasting for 2-3 ms. These upstrokes are reminiscent of salient structures found in natural grasshopper communication signals, suggesting that precise spikes selectively encode particularly important aspects of the natural stimulus environment.