ELECTROPHYSIOLOGY STUDIES OF PSYCHOMOTOR PROCESSES

这项研究的总体目标是确定解剖结构， 生理机制，并在可能的情况下， 与表面记录的事件相关电位（ERP）相关的基底 与感觉运动和认知过程有关ERP是唯一的实时 人类大脑活动的生理指标， 各种各样正常和异常的大脑活动我们利用 未麻醉的、行为正常的旧大陆猴子（M. fascicularis），如 研究人类ERPS的最接近可行模型。的定时和 硬膜外波形的分布是 分析.这些数据可以与人类头皮记录的ERP进行比较 并形成关于潜在发电机的特定假设的基础。 颅内电生理研究利用三个免费的 程序，每一个敏感的神经活动的不同方面， 神经元的集合：1）皮层内的振幅最大值和平面 对于场电位的所有分量确定极性反转 使用可移动的16通道多触点电极，2）净点火水平 通过记录局部神经元的多单位活动（MUA）来测量局部神经元的活动。 每个部位和ERP中的每个时间点，3）局部向外和向内 从场电位估计神经跨膜电流 一维电流源密度（CSD）分析。这些 组合的方法提供精确的时间和空间分辨率 同时允许同时探索整个层流广阔的 活跃皮层因此，我们可以评估神经激活的模式， 跨膜电流的区域和这种活动的贡献 到表面/头皮数据。整个纹层的活动顺序， 也可以评估跨皮层区域的运动。具体研究将包括 检查与模式相关的活动的层状分布 纹状体和纹状体外视皮层内刺激，大脑 与训练的自发手部运动相关的活动， 与视觉和听觉辨别能力相关的电位 任务这些研究的一个主要重点将是检查 皮层内和表面ERP的神经递质操纵。 抑制回路将通过局部注射 GABA-A拮抗剂荷包牡丹碱;兴奋回路被认为是 与“赫布”突触修饰相关的研究将通过使用 竞争性和非竞争性NMDA受体拮抗剂。在每个 将结构化电生理数据与已知的 细胞成分和突触接触的模式以及 特定神经递质的分布， 放射自显影和免疫细胞化学技术。

The overall goal of this research is to define the anatomical structures, physiological mechanisms and, whenever possible, the neurochemical substrates of surface-recorded Event Related Potentials (ERP) associated with sensory, motor and cognitive processes. ERP are the only real-time physiologic measure of brain activity available in humans and they index a wide variety of normal and deviant brain processes. We utilize unanesthetized, behaving old world monkeys (M. fascicularis), as the closest feasible model for the study of human ERPS. The timing and distribution of the epidural waveform is the starting point for the analysis. These data allow comparison with scalp-recorded ERPs in humans and form the basis for specific hypotheses regarding underlying generators. Intracranial electrophysiological studies utilize three complimentary procedures, each sensitive to a different aspect of neural activity within ensembles of neurons: 1) amplitude maxima and planes of intracortical polarity inversion are determined for all components of the field potential using a moveable 16 channel multicontact electrode, 2) the net firing level of local neurons is measured by recording multiple unit activity (MUA) for each site and for each time point in the ERP, 3) local outward and inward neural transmembrane current flows are estimated from the field potential data by one-dimensional current source density (CSD) analysis. These methods in combination provide precise temporal and spatial resolution while permitting simultaneous exploration of the entire laminar expanse of active cortex. Thus, we can evaluate patterns of neural activation in the regions of transmembrane current flow and the contribution of this activity to the surface/scalp data. The sequencing of activity across laminae and across cortical regions can also be assessed. Specific studies will include examination of the laminar distribution of activity associated with pattern stimulation within striate and extra-striate visual cortex, cerebral activity associated with trained self -initiated hand movements and the potentials related to the performance of visual and auditory discrimination tasks. A principal focus of these studies will be examining the effects of neurotransmitter manipulation on the intracortical and surface ERP. Inhibitory circuitry will be manipulated by localized injections of the GABA-A antagonist bicuculline; excitatory circuits believed to be associated with 'Hebbian' synaptic modification will be explored by using competitive and noncompetitive NMDA receptor antagonists. Within each structure electrophysiologic data will be compared to known distribution of cellular elements and the pattern of synaptic contacts as well as the distribution of specific neurotransmitters as determined by autoradiographic and immunocytochemical techniques.