Who reads temporal information contained across synchronized and oscillatory spike trains?
Who reads temporal information contained across synchronized and oscillatory spike trains?
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DOI：
10.1038/27201
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发表时间：
1998-10-15
期刊：
影响因子：
64.8
通讯作者：
Laurent, G
中科院分区：
文献类型：
--
作者：
MacLeod, K;Bäcker, A;Laurent, G
我们对感知背后的大脑机制的推断依赖于大脑是否有可能从许多神经元的尖峰序列中包含的信息中“重建”刺激（1-5）。大脑实际上是如何完成这种重建的，这在很大程度上仍然是未知的。哺乳动物大脑中的振荡和同步活动与不同的行为状态或复杂认知任务的执行相关（6-11），并被认为参与了个体特征与更复杂感知的“结合”（12-14）。但是，如果同步确实是相关的，那么是什么感觉到它呢？在昆虫中，早期嗅觉系统中的振荡同步活动似乎是精细气味辨别所必需的（15），并且能够编码关于相对于振荡“时钟”的尖峰时间的刺激的信息（16）。在这里，我们研究这些相干振荡信号的解码。我们确定了一个群体的神经元下游的气味激活，同步的神经元组件。这些下游神经元显示气味反应，当它们的输入被去刺激时，其特异性降低。这种选择性的退化包括对新气味的反应的出现和由不同气味引起的尖峰序列的辨别力的丧失。这种信息的丢失在其活动被去激活的上游神经元中从未被观察到。这些结果表明，在时间上编码的信息跨越神经元的集合收敛到通路下游的单个神经元上。
Our inferences about brain mechanisms underlying perception rely on whether it is possible for the brain to 'reconstruct' a stimulus from the information contained in the spike trains from many neurons(1-5). How the brain actually accomplishes this reconstruction remains largely unknown. Oscillatory and synchronized activities in the brain of mammals have been correlated with distinct behavioural states or the execution of complex cognitive tasks(6-11) and are proposed to participate in the 'binding' of individual features into more complex percepts(12-14). But if synchronization is indeed relevant, what senses it? In insects, oscillatory synchronized activity in the early olfactory system seems to be necessary for fine odour discrimination(15) and enables the encoding of information about a stimulus in spike times relative to the oscillatory 'clock'(16). Here we study the decoding of these coherent oscillatory signals. We identify a population of neurons downstream from the odour-activated, synchronized neuronal assemblies. These downstream neurons show odour responses whose specificity is degraded when their inputs are desynchronized. This degradation of selectivity consists of the appearance of responses to new odours and a loss of discrimination of spike trains evoked by different odours. Such loss of information is never observed in the upstream neurons whose activity is desynchronized. These results indicate that information encoded in time across ensembles of neurons converges onto single neurons downstream in the pathway.