Effect of oscillations on coding and connectivity in monkey sensorimotor cortex

描述（由申请人提供）：研究大脑的电生理学家必须经常选择是观察森林还是树木：脑电图（EEG）和局部场电位（LFP）测量大量神经元的宏观振荡，而单个单位记录测量单个细胞产生的微观电位。我们建议在运动皮层中检查这两者之间的关系，其中高频（10- 45 Hz）振荡是常见的。这些振荡明显受到行为的调节，但一些作者认为它们是在没有运动的情况下皮质失活的症状，而其他人则认为它们在分布的皮质区域的感觉运动整合中发挥作用。众所周知，振荡会影响许多运动皮层细胞产生动作电位的时间，但这种效应的意义-发生在两个分析水平的交叉点-并没有得到很好的理解。我们建议研究这些振荡的行为相关性和振荡结构对神经元棘波中编码和传递的信息的影响。我们将使用高密度的100个电极阵列记录运动和运动前区皮层的单个单元和LFP，这些电极阵列植入行为猴子的初级运动、腹侧运动前区和背侧运动前区皮层。这些猴子已经被训练来执行简单的达到任务，包括重复移动到视觉指示的目标。在最初的一组实验中，我们将尝试将与选择和计划运动相关的振荡活动与保持静止姿势相关的活动分离。在第二组实验中，我们将研究LFP功率和相位对神经尖峰中编码的运动学信息的影响。在第三组实验中，我们将使用统计方法和更直接地通过评估在正在进行的全局振荡的不同阶段施加的电刺激的传播来检查振荡结构对功能连接的影响。公开声明：全局振荡是疾病和健康中大脑活动的标志;它们与注意力、感觉和记忆等高阶功能有关，并且在帕金森病和癫痫等病理学中发挥重要作用。尽管振荡是大脑活动的一个普遍特征，但它对神经信息处理的影响（如果有的话）尚不清楚。我们将使用高密度多电极阵列记录行为猴子的大脑活动，并使用这些数据来评估振荡对产生运动行为的神经回路的影响。

DESCRIPTION (provided by applicant): Electrophysiologists studying the brain must often choose whether to observe the forest or the trees: electroencephalogram (EEG) and local field potentials (LFP) measure macroscopic oscillations in large populations of neurons, while single unit recordings measure microscopic potentials generated by single cells. We propose to examine the relationship between these two in motor cortex, where high frequency (10- 45Hz) oscillations are commonly observed. These oscillations are clearly modulated by behavior, but some authors have argued that they are a symptom of cortical inactivation in the absence of movement, while others have suggested they serve a role in sensorimotor integration across distributed regions of cortex. It is well known that oscillations affect the timing of action potentials generated by many motor cortical cells, but the significance of this effect - which occurs at the intersection of two levels of analysis - is not well understood. We propose to examine the behavioral relevance of these oscillations and the effect of oscillatory structure on the information encoded and communicated in neuronal spikes. We will record single units and LFPs from motor and pre-motor cortex using high-density, 100-electrode arrays implanted in primary motor, ventral pre-motor, and dorsal pre-motor cortex in behaving monkeys. These monkeys have been trained to perform simple reaching tasks that involve repeated movements to visually-instructed targets. In an initial set of experiments, we will attempt to dissociate the oscillatory activity associated with selecting and planning a movement with the activity associated with maintaining a stationary posture. In a second set of experiments, we will examine the impact of LFP power and phase on the kinematic information encoded in neural spiking. In a third set of experiments, we will examine the effect of oscillatory structure on functional connectivity using both statistical methods and more directly by assessing the propagation of electrical stimulation applied at different phases of the ongoing global oscillation. Public Statement: Global oscillations are a hallmark of brain activity in both sickness and in health; they have been related to higher order functions such as attention, sensation, and memory, and they play an important role in pathologies such as Parkinson's disease and epilepsy. Despite being a ubiquitous feature of brain activity, it is not clear what effect, if any, oscillations have on neural information processing. We will record brain activity in behaving monkeys using high-density multi-electrode arrays, and use this data to assess the effects of oscillations on the neural circuitry involved in generating motor behavior.