The Structure of Olfactory Neural and Perceptual Spaces

项目总结(项目4：嗅觉、神经和知觉空间的结构) 目前尚不清楚刺激驱动的神经活动如何导致感知。虽然此问题通常是 从前馈的角度来看--刺激有系统地变化为神经活动和知觉 嗅觉系统构成了一个特殊的挑战，因为驱动 神经反应没有被很好地定义。在这里，我们建议一种替代方法：与其从 鼻子中的感受器，我们建议从感知向后工作。也就是说，我们将利用多样化的 概念和技术创新，以构建一种新型的“尺子”，使我们能够准确地测量 气味之间的感知距离，然后用这把尺子全面绘制出 感知气味空间，首先是人类，然后是老鼠。同时，我们将利用神经科学的进步。 成像技术第一次让我们能够在清醒的小鼠身上看到皮质对气味的反应。 重要的初步数据表明，梨状皮质具有系统性和不变性。 气味空间的表示，并且这个空间与气味之间的知觉关系相关。通过 评估皮质和知觉对同一组气味的反应，这些实验将揭示如何 关于气味化学的信息是在大脑皮层组织的，以及这些信息如何与感觉相关，两者都是 无论是在老鼠身上还是在人类身上。限制神经和感知气味空间的维度和结构，在 一种系统和全面的方式，将揭示嗅觉输入输出功能的关键方面 系统。

Project Summary (Project 4: The structure of olfactory neural and perceptual spaces) It is not clear how stimulus-driven neural activity leads to perception. While this problem is typically approached from a feed-forward perspective — stimuli are systematically varied as neural activity and perception are monitored — the olfactory system poses a particular challenge, as the molecular stimulus space that drives neural responses is not well defined. Here we suggest an alternative approach: rather than working forward from receptors in the nose, we propose to work backwards from perception. That is, we will take advantage of a variety of conceptual and technical innovations to construct a new type of “ruler” that will allow us to accurately measure perceptual distances between odors, and then use this ruler to comprehensively map out the global structure of perceptual odor space, first in humans and then in mice. In parallel we will take advantage of advances in neural imaging technologies that give us, for the first time, access to cortical responses to odorants in awake mice. Important preliminary data demonstrates that the piriform cortex harbors a systematic and invariant representation of odor space, and that this space correlates with perceptual relationships amongst odors. By assessing both cortical and perceptual responses to the same odorant set, these experiments will reveal how information about odorant chemistry is organized in cortex, and how this information relates to perception, both in mice and in humans. Constraining the dimensionality and structure of neural and perceptual odor spaces, in a systematic and comprehensive fashion, will reveal key aspects of the input-output function of the olfactory system.