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，而单单元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- 45Hz）振荡通常被观察到。这些振荡明显受到行为的调节，但一些作者认为，它们是在缺乏运动的情况下皮层失活的症状，而另一些人则认为，它们在皮层分布区域的感觉运动整合中起作用。众所周知，振荡影响许多运动皮质细胞产生动作电位的时间，但这种影响的意义-发生在两个分析水平的交叉点-尚未得到很好的理解。我们建议研究这些振荡的行为相关性以及振荡结构对神经元尖峰中编码和交流信息的影响。我们将使用高密度、100个电极阵列植入行为猴子的初级运动皮层、腹侧前运动皮层和背侧前运动皮层，记录来自运动和前运动皮层的单个单元和lfp。这些猴子经过训练，可以完成简单的接触任务，包括向视觉指示的目标重复动作。在最初的一组实验中，我们将尝试分离与选择和计划运动相关的振荡活动与与保持静止姿势相关的活动。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球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通性的影响。公开声明：全球振荡是疾病和健康状态下大脑活动的标志；它们与注意力、感觉和记忆等高级功能有关，并且在帕金森病和癫痫等疾病中起着重要作用。尽管振荡是大脑活动的一个普遍特征，但目前尚不清楚振荡对神经信息处理有什么影响，如果有的话。我们将使用高密度多电极阵列记录猴子的大脑活动，并利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.