Intracortical Connections Underlying Cortical Function

9221854吉尔伯特大脑感觉皮层中的神经细胞被位于某个空间区域的刺激激活，该区域称为细胞的“感受野”。来自身体表面触觉(体感系统)的研究证据表明，成年人的这些感受场在位置和大小上都是令人惊讶的动态的，而不是特定细胞的固定特征。活跃的感觉体验对于定义感受野很重要；周围区域的感觉丧失会缩小该区域皮质细胞感受野的大小，而持续的刺激会导致感受野的增加。最近的努力是确定当这些可塑性变化发生时，神经元通路中的连接是如何被修改的。这项研究是一种新的应用，类似于体感方法，但使用视觉皮质来探索视觉通路和皮质内联系的已知细节。在这里，我们研究了当部分视野变得不可见(暗点)时，视觉系统中感受野的变化。解剖学和药理学将被用来检查与皮质和皮质内的联系，以区分这种联系在皮质动力学中的作用。这些研究将有助于阐明跨空间整合信息和皮质记忆的机制；重点是视觉处理，但结果将产生影响，从视觉神经科学到一般的感觉神经科学，以及认知神经科学。***

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. ***