ANTERIOR PARIETAL REPRESENTATION OF MOVING SKIN STIMULI

此申请旨在为一个协调的研究计划提供资金 包括麻醉松鼠猴的实验和模拟 神经生物学上忠实的神经网络的研究。动物 实验将集中在前顶叶（SI）皮质反应， 恒速刷牙刺激施加到猴的手，并将 采用新开发的功能成像技术（近红外- IR - 光学成像）。红外成像方法将用于（1）观察和 描述SI的大尺度时空模式的发展 活动所产生的这种刺激，并在同一实验中，（2）， 指导微电极穿透的放置， 单个神经元和小神经聚集体的活动从 不同功能特征的区域的刺激诱发的全球 活动模式选择了所采用的刺激条件 因为他们以前证明有能力生产（1）- 人类主体对运动刺激属性判断的修正 如开/关轨迹、横移长度和运动方向;（2） S1神经元对触觉运动的反应的短期变化 感受野;和/或（3）大规模重组，重复 刺激诱发的全局SI活动模式的刺激应用。 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，包括 （1）最近描述的SI方式的显式公式 地形组织（“隔离”组织计划），（2） SI的径向和横向内在连通性，（3）“经典”快速- 作用GABA能和多巴胺能神经递质系统，以及 作用时间较长的胆碱能神经调节系统 当然，（4）细胞/分子机制的子集 （包括电压门控和/或激动剂门控膜离子载体） 新皮层神经元的特征，和-（5）非线性 单个SI的不同树突区室之间的相互作用 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.