Intracortical Connections Underlying Cortical Function

9221854 Gilbert 大脑感觉皮层中的神经细胞被位于特定空间区域内的刺激激活，该空间区域称为细胞的"感受野"。 来自身体表面触觉（体感系统）的研究证据表明，成年人的这些感受野在位置和大小上是惊人的动态变化，而不是具有特定细胞的固定特征。 主动感觉体验对于定义感受野是重要的;来自外围区域的感觉的丧失减小了该区域的皮层细胞的感受野的大小，并且持续的刺激导致增加。 最近的努力已经建立了如何在神经元通路的连接被修改时，这些塑料的变化发生。 这项研究是一个新的应用程序，平行的体感方法，但使用视觉皮层利用已知的细节的视觉通路和皮质内连接。 在这里，在视觉系统中的感受野的变化进行了研究，当部分的视野是不可见的（暗点）。 解剖学和药理学将被用来检查连接和皮质内，以区分皮质动力学中的这种连接的贡献。 这些研究将有助于阐明跨空间整合信息和皮层记忆的机制;重点是视觉处理，但其结果将影响视觉神经科学之外的感觉神经科学和认知神经科学。 ***

9221854 Gilbert A nerve cell in the sensory cortex of the brain is activated by stimuli that lie within a certain spatial area, called the "receptive field" of the cell. Evidence from work on the sense of touch on the body surface (somatosensory system) has shown that these receptive fields in adults are surprisingly dynamic in location and size, rather than having fixed characteristics for a given cell. Active sensory experience is important for defining the receptive field; a loss of sensation from the peripheral area reduces the size of receptive fields of cortical cells for that area, and persistent stimulation leads to an increase. Recent efforts have been to establish how connections in the neuronal pathway are modified when these plastic changes occur. This study is a novel application that parallels somatosensory approach, but uses the visual cortex to exploit known details of the visual pathway and intracortical connections. Here, changes in receptive fields in the visual system are studied when part of the visual field is made invisible (a scotoma). Anatomy and pharmacology will be used to examine connections to and within the cortex, to differentiate the contributions of such connections in the cortical dynamics. These studies will help elucidate the mechanisms of integrating information across space, and of cortical memory; the emphasis is on visual processing, but the results will have impact beyond visual neuroscience to sensory neuroscience in general, and to cognitive neuroscience. ***