ANTERIOR PARIETAL REPRESENTATION OF MOVING SKIN STIMULI

这项申请为一个协调的研究项目寻求资金。 由麻醉松鼠猴实验和模拟组成 神经生物学忠实神经网络的研究。这只动物 实验将集中在前顶叶(SI)的皮质反应 恒速刷牙刺激应用于猴的手，并将 采用新开发的功能成像技术(近红外 -光学成像)。将使用红外成像方法(L)观察和 描述SI大尺度时空分布发展的特征 由这种刺激产生的活动，在相同的实验中，(2)到 引导微电极穿透的位置，以使放电 单个神经元和小神经集合体的活动从 刺激诱发的全局的不同功能特征区域 活动模式。选择了要采用的刺激条件 因为他们以前证明有能力生产(1)- 被试对运动刺激属性判断的修正 例如开/关轨迹、导线长度和移动方向；(2) 大脑皮层内SI神经元对触觉运动反应的短期变化 感受野；和/或(3)大规模重组，具有重复性 刺激应用，刺激诱发的全球SI活动模式。 神经生理学和红外成像的机制解释 在动物实验中获得的观察结果将通过 模型神经网络的协调仿真研究 (L)最近描述的一种SI方式的显式表示 地形组织(“隔离”组织计划)，(2) SI的径向和侧向本征连通性，(3)“经典”快速连通性。 起作用的GABA能和谷氨酸能神经递质系统以及 作用时间较长的胆碱能神经调节系统 当然，(4)细胞/分子机制曲目的子集 (包括电压门控和/或激动剂门控的膜离子载体) 新皮质神经元的特征，以及-(5)非线性 个体SI不同树突间的相互作用 神经元。

This application seeks funding for a coordinated research program consisting of experiments on anesthetized squirrel monkeys and simulation studies of a neurobiologically-faithful neural network. The animal experiments will focus on the anterior parietal (SI) cortical response to constant-velocity brushing stimuli applied to the monkey hand, and will employ a newly-developed functional imaging technology (near-infrared - IR - optical imaging). The IR imaging method will be used (l) to observe and characterize development of the large-scale spatiotemporal patterns of SI activity produced by such stimuli and, in the same experiments, (2) to direct the placement of microelectrode penetrations so that the discharge activity of single neurons and small neural aggregates is sampled from different functionally characterized regions of the stimulus-evoked global activity pattern. The stimulus conditions to be employed were selected because of their previously demonstrated capacity to produce (1)- modifications of human subjects' judgements of moving stimulus attributes such as the on/off locus, traverse length, and direction of movement; (2) short-term changes in SI neuron response to tactile motion within the receptive field; and/or (3) large-scale reorganization, with repetitive stimulus application, of the stimulus-evoked global SI activity pattern. Mechanistic explanations for the neurophysiological and IR imaging observations obtained in the animal experiments will be sought through coordinated simulation studies of a model neural network which includes explicit formulations of (l) a recently described manner of SI topographical organization (the "segregate" plan of organization), (2) the radial and lateral intrinsic connectivity of SI, (3) the "classical" fast- acting GABAergic and glutaminergic neurotransmitter systems, as well as the cholinergic neuromodulatory system whose actions are of longer time course, (4) a subset of the repertoire of cellular/molecular mechanisms (including voltage- and/or agonist-gated membrane ionophores) characteristic of neocortical neurons, and -(5) the non-linear interactions between the different dendritic compartments of individual SI neurons.