INPUT/OUTPUT RELATIONSHIPS IN VISUAL CORTEX

拟议中的实验调查了 各种类型传入物的终止方式和 突起神经元的树突分枝模式 不同的目标。提出的两个具体问题是：1) 不同传出靶点的皮质神经元是否有不同 树枝分枝的模式？2)不同的来源是如何 根据这些模式的传入终止 树木化？这项研究将在猫后部进行 内侧外侧丘上沟(PMLS)是一个有 不同的传入来源以及多个皮质和 皮质下传出靶点。第一个问题是 使用稍微固定的切片制备方法来接近 细胞内注射退行性变的V层神经元 来自三个已知地区的标签，它们在 视觉信息的处理，上丘、脑桥、 同侧纹状皮质。树枝状组织的形态 投射到这些区域的神经元将被比较，以便 确定传入模式是否存在差异 取样。投射到其中两个部位的神经元，通过 侧支，也将被逆行标记并在细胞内 注射以确定它们是否在形态上是不同的 从只投射到两个部位之一的神经元。这个 第二个问题将通过制定单独的 三区离子导入顺行示踪剂注射 被认为对这种独特的生理特性负责 在PMLS神经元中，后外侧/枕复合体， 板内核团和同侧纹状皮质。 顺行填充的轴突及其周围将被绘制并 它们的分布与不同的树枝状图案相比较 V层投射神经元。通过研究两者之间的关系 输入到PMLS的输出神经元，希望结果将 有助于理解该地区在视觉运动中的作用 行为。

The proposed experiments investigate the relationship between the pattern of termination of various types of afferents and the pattern of dendritic arborization of neurons that project to different targets. The two specific questions being posed are: 1) Do cortical neurons with different efferent targets have different patterns of dendritic arborization? 2) How do different sources of afferents terminate with respect to those patterns of arborization? This study will be carried-out in cat Posterior Medial Lateral Suprasylvian Sulcus (PMLS), a visual area with diverse sources of afferents as well as multiple cortical and subcortical efferent targets. The first question will be approached using a lightly fixed slice preparation to intracellularly inject layer V neurons that have been retrogradely labeled from three regions known to play different roles in the processing of visual information, the superior colliculus, pons, and ipsilateral striate cortex. The dendritic morphologies of neurons that project to these areas will be compared in order to determine if there are differences in patterns of afferent sampling. Neurons that project to two of these sites, via collaterals, will also be retrogradely labeled and intracellularly injected in order to determine if they are morphologically distinct from the neurons that project to only one of the two sites. The second question will be approached by making separate sets of iontophoretic injections of anterograde tracer into three regions thought to be responsible for the unique physiological properties of PMLS neurons, the lateral posterior/pulvinar complex, the intralaminar nuclei, and the ipsilateral striate cortex. Anterogradely filled axons and their boutons will be drawn and their distribution compared with the different dendritic patterns of layer V projecting neurons. By studying the relationship of input to output neurons in PMLS, it is hoped that the results will contribute to an understanding this region's role in visuomotor behavior.