Oscillation and Temporal Encoding of Olfactory Info

描述（由申请人提供）：来自人脑的脑电图记录显示复杂的波形-通常是振荡的-具有许多不同频段的能量。这种活动（例如，40赫兹信号的能量）通常是状态依赖的，并随着受试者的注意力或清醒而变化。一些最剧烈的调节发生在睡眠的不同阶段。这些宏观信号通常代表了大量神经元的同步活动，这些神经元周期性地放电，在所有哺乳动物、非哺乳动物脊椎动物和较小的动物（如昆虫和软体动物）中都存在。然而，这些信号的功能相关性，以及引起它们的信号的功能相关性，在很大程度上仍然是推测性的。目前的工作旨在破译这些神经、分布和协调现象中的一些，并提供对它们存在的功能和计算理解。该方法利用了小神经系统（昆虫大脑）的可及性和嗅觉回路中这种协调现象的普遍性（昆虫嗅觉系统：触角叶和蘑菇体）。使用的方法是电生理（细胞内和多单单位记录）和计算（定量分析，模拟）。由于昆虫和哺乳动物的嗅觉回路非常相似，这项工作的潜在回报是更好地理解神经编码、嗅觉表征以及大脑回路中记忆的一般形式。例如，表征稀疏性的基本问题（即，记忆应该由神经集合的大子集还是小子集来表示）可以直接研究，而这在今天的哺乳动物的大大脑中是不可能的。因此，这项工作将与目前破译啮齿动物和灵长类动物的记忆回路以及人类大脑使用的编码策略的努力相关。

DESCRIPTION (provided by applicant): Electroencepholographic recordings from the human brain reveal complicated waveforms - often oscillatory - with energy in many different frequency bands. This activity (e.g., the energy of 40 Hz signals) is usually state-dependent and varies with the subject's attentiveness or wakefulness. Some of the most dramatic modulations occur in the different phases of sleep. These macroscopic signals generally represent the synchronized activity of large numbers of neurons that fire periodically and occur in all mammals, non-mammalian vertebrates and smaller animals such as insects and molluscs. The functional relevance of these signals -thus, of the signals that cause them-remains, however, largely conjectural. The present work is directed at deciphering some of these neural, distributed and coordinated phenomena and at providing a functional and computational understanding of their existence. The approach exploits the accessibility of small nervous systems (insect brains) and the prevalence of such coordinated phenomena in olfactory circuits (insect olfactory system: antennal lobe and mushroom bodies). The methods used are electrophysiological (intracellular and multi-single unit recordings) and computational (quantitative analysis, simulations). Because olfactory circuits in insects and mammals are so alike, the potential payoff of this work is a better understanding of neural coding, olfactory representations and of the format of memories in brain circuits in general. For example, the fundamental problem of representation sparsity (i.e., whether a memory should be represented by a large or small subset of a neural assembly) can be studied directly in ways that are impossible today with the large brains of mammals. This work will thus have relevance to present efforts to decipher memory circuits in rodents and primates and coding strategies used by the human brain.