Temporal Coding in an Olfactory Circuit

[9511764]劳伦特尽管人们认为大脑和计算机非常相似，但它们用于编码和存储信息的机制却有着根本的不同。这在一定程度上是因为计算机是由工程师们利用形式逻辑工具来解决相当有限的问题而开发出来的，而大脑是在进化的选择压力下经过数百万年发展起来的，是唯一的工程师。事实上，大脑的进化是为了增加“主人”的生存机会，因此主要是为了方便发现猎物、捕食者和配偶。因此，他们成功地解决了非常复杂的模式识别问题，而目前的计算机在处理这些问题方面出了名的差。我们如何识别像一张脸或一种气味这样复杂的东西，我们如何存储它们无数可能的外观，我们的大脑如何用神经元活动模式来表示它们？要理解这一点，我们必须理解神经系统中的编码；我们需要确定大脑中刺激表征背后的规则。大脑编码的传统观点认为，信息存在于每单位时间产生的脉冲的平均数量中（速率编码）；神经元群产生的脉冲的相对定时的作用还没有被仔细地评估过。这位年轻科学家的工作集中在处理气味的电路上。实验旨在确定神经元脉冲的相对时间（时间编码）是否是信息的潜在载体。

9511764 Laurent Although brains and computers are thought to be quite similar, the mechanisms which they use to encode and store information are fundamentally different. This is partly because computers were developed by engineers using tools of formal logic to solve rather limited sets of problems, while brains were developed over millions of years with selective pressure of evolution as the only engineer. Indeed, brains evolved to increase the chances of survival of their "owners", and thus primarily to facilitate the detection of prey, predators and mates. Consequently, they succeeded in solving the very complex problems of pattern recognition, problems which present computers are notoriously poor at handling. How do we recognize something as complex as a face or an odor, how do we store their infinite number of possible appearances, how does our brain represent them with neuronal activity patterns? To understand this, we must understand coding in the nervous system; we need to determine the rules that underlie stimulus representation in the brain. Conventional views of coding by the brain hold that information resides in the average number of impulses produced per unit time (rate coding); the role of relative timing of impulses produced by groups of neurons has not been carefully evaluated. The work of this young scientist focuses on circuits that process smells. Experiments are designed to determine whether the relative timing of neuronal impulses (temporal coding) is a potential carrier for information.