Centre de Neurosciences Paris Sud, UMR CNRS 8195, Université Paris-Sud, 91405 Orsay Cedex, France.
Hear Res. 2011 Jan;271(1-2):147-58. doi: 10.1016/j.heares.2010.01.010. Epub 2010 Jan 29.
Over the last 15 years, an increasing number of studies have described the responsiveness of thalamic and cortical neurons to communication sounds. Whereas initial studies have simply looked for neurons exhibiting higher firing rate to conspecific vocalizations over their modified, artificially synthesized versions, more recent studies determine the relative contribution of "rate coding" and "temporal coding" to the information transmitted by spike trains. In this article, we aim at reviewing the different strategies employed by thalamic and cortical neurons to encode information about acoustic stimuli, from artificial to natural sounds. Considering data obtained with simple stimuli, we first illustrate that different facets of temporal code, ranging from a strict correspondence between spike-timing and stimulus temporal features to more complex coding strategies, do already exist with artificial stimuli. We then review lines of evidence indicating that spike-timing provides an efficient code for discriminating communication sounds from thalamus, primary and non-primary auditory cortex up to frontal areas. As the neural code probably developed, and became specialized, over evolution to allow precise and reliable processing of sounds that are of survival value, we argue that spike-timing based coding strategies might set the foundations of our perceptive abilities.
在过去的 15 年中，越来越多的研究描述了丘脑和皮层神经元对通讯声音的反应。虽然最初的研究只是简单地寻找对同种发声表现出更高放电率的神经元，而不是它们的修改后的、人为合成的版本，但最近的研究确定了“率编码”和“时间编码”对尖峰序列传递的信息的相对贡献。在本文中，我们旨在回顾从人工到自然声音，丘脑和皮层神经元用于编码关于声刺激的信息的不同策略。考虑到简单刺激获得的数据，我们首先说明，从严格的尖峰定时与刺激时间特征之间的对应关系到更复杂的编码策略，时间编码的不同方面已经存在于人工刺激中。然后，我们回顾了一些证据表明，从丘脑、初级和非初级听觉皮层到额叶区域，尖峰定时提供了一种有效的编码策略，用于区分通讯声音。由于神经编码可能是在进化过程中为了精确和可靠地处理对生存有价值的声音而发展和专门化的，我们认为基于尖峰定时的编码策略可能为我们的感知能力奠定了基础。
