Contextual modulation in the mammalian primary visual cortex: linking neural circuits to perception

哺乳动物初级视觉皮层的情境调节：将神经回路与感知联系起来

• 批准号: RGPIN-2015-06761
• 负责人: Crowder, Nathan
• 金额: $ 2.91万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=648336
• 关键词: Contextual; modulation; mammalian; primary; visual

It is widely appreciated that the brain has a remarkable capacity to process incoming information. The overall goal of my research is to understand the processes happening in the brain that allow us to see the world around us. Although the eyes detect light, most of what is commonly thought of as vision actually arises from analyses performed by a chain of interconnected brain regions called the geniculo-striate pathway. *** Research in my laboratory focuses on the first cortical stage of this pathway called the primary visual cortex (V1) where individual brain cells (or neurons) have the ability to detect basic features in a visual scene such as lines of a specific orientation at a particular location in space. The selectivity of an individual V1 neuron can change based on what has been seen previously, the spatial layout of the scene, or even what the animal is doing at the time. Studying this 'contextual modulation' will give a more complete understanding of how V1 works because vision in everyday life has a temporal, spatial, and behavioral context.*** It has long been conjectured that both the basic properties of V1 neurons and contextual modulation arise through specific connections between different types of neurons called neural circuits. Efforts to link neural circuits with perception have been aided by recently developed tools in the field of optogenetics that make it possible to stimulate or suppress specified types of neurons in a circuit by shining light on them. Optogenetic tools are mainly applied in mice, and I have extensive experience working with this species.*** In my novel and exciting research program, members of my lab will use optogenetics in mice to study several aspects of contextual modulation for the first time. Our first objective is to study how inactivating V1 or brain areas that connect with it affects context coding. Our second objective is to isolate the roles of specified types of V1 neurons in contextual modulation. Our third objective is to establish techniques to study visual perception in awake mice to bridge the gap between neural circuits and perception. *** The proposed work will benefit the visual neuroscience community by providing a more comprehensive understanding of how the properties of V1 neurons arise from specific cell types arranged in neural circuits. This will help improve existing models of how the brain codes visual information, and may provide insights into how information is represented more generally across the nervous system. A better understanding of how the brain encodes visual information could also inspire biomimetic algorithms for computer vision and artificial intelligence. Although it is a distant goal at present, the development of a seeing machine with the ability to use visual information to interact with its surroundings just as well as humans (or even mice) would have far reaching applications ranging from security, to manufacturing, to space exploration.**

人们普遍认为，大脑具有处理传入信息的非凡能力。我研究的总体目标是了解大脑中发生的过程，使我们能够看到我们周围的世界。虽然眼睛能探测到光线，但大多数通常认为的视觉实际上是由一系列相互连接的大脑区域进行的分析产生的，这些区域被称为膝丘-纹状体通路。***我实验室的研究主要集中在这条通路的第一个皮层阶段，称为初级视觉皮层（V1），在这个阶段，单个脑细胞（或神经元）有能力检测视觉场景中的基本特征，比如空间中特定位置的特定方向的线条。单个V1神经元的选择性可以根据之前看到的东西，场景的空间布局，甚至动物当时正在做的事情而改变。研究这种“上下文调制”将使我们更全面地了解V1是如何工作的，因为日常生活中的视觉具有时间、空间和行为背景。***长期以来，人们一直推测V1神经元的基本特性和上下文调制都是通过称为神经回路的不同类型神经元之间的特定连接产生的。最近在光遗传学领域开发的工具有助于将神经回路与感知联系起来，这些工具可以通过光照刺激或抑制回路中特定类型的神经元。光遗传学工具主要应用于小鼠，我对这一物种有丰富的研究经验。***在我新颖而令人兴奋的研究项目中，我的实验室成员将首次在小鼠身上使用光遗传学来研究情境调制的几个方面。我们的第一个目标是研究V1或与之相连的大脑区域的失活是如何影响上下文编码的。我们的第二个目标是分离特定类型的V1神经元在上下文调制中的作用。我们的第三个目标是建立研究清醒小鼠视觉感知的技术，以弥合神经回路和感知之间的差距。***建议的工作将通过提供对V1神经元的特性如何从神经回路中排列的特定细胞类型产生的更全面的理解而使视觉神经科学界受益。这将有助于改进关于大脑如何编码视觉信息的现有模型，并可能提供关于信息如何在神经系统中更普遍地表示的见解。更好地理解大脑如何编码视觉信息，也可以启发计算机视觉和人工智能的仿生算法。虽然目前这是一个遥远的目标，但开发一种能够使用视觉信息与周围环境互动的机器，就像人类（甚至老鼠）一样，将在安全、制造、太空探索等领域有着深远的应用