Neural Basis of Saccade Preparation

描述（由申请人提供）：眼神经系统由竞争网络中的交替活动模式控制，这些活动模式产生扫视并保持注视。当两个网络之间的操作得到适当维护时，眼球运动功能是正常的。然而，活动平衡的偏差可能导致功能障碍。例如，降低注视网络的功效或增强扫视生成网络的活动会损害延迟或抑制运动的能力。这项提议旨在研究这些网络中神经元的活动，以及在改变两者之间平衡的扰动期间对行为的影响。重点是明确的上级丘，其嘴极参与保持固定和尾部区域是必不可少的产生扫视。选择的扰动是通过在受试者执行各种眼科任务时向眼睛递送空气抽吸来诱导眨眼。眨眼已经被证明会损害脑桥水平的扫视抑制网络的完整性，并且如果眨眼是在呈现扫视目标（并且允许发起运动）之后触发的，则目标导向的运动以减少的延迟伴随眨眼。具体目标1检查了眨眼对上级丘中的注视和扫视生成网络的影响。它专门测试了眨眼抑制注视网络（喙侧）活动的假设 区域）并增加扫视生成网络（尾部区域）的兴奋性。具体目标2检查是否潜在的神经活动时过早触发扫视编码运动前信息。本章将具体检验运动准备假说的阈值原理以及空间注意和运动准备是否可以分离。我们预计，行为和神经生理学方法的结合将提供对神经精神疾病（例如，注意力不集中症，精神分裂症）特征是不能抑制反射性运动。

DESCRIPTION (provided by applicant): The oculomotor repertoire is governed by alternating activity patterns in competing networks that generate saccades and preserve fixation. When the operation between the two networks is properly maintained, eye movement function is normal. A bias in the balance of activity, however, can lead to dysfunction. For example, decreasing the efficacy of the fixation network or enhancing the activity of the saccade generation network compromises the ability to delay or inhibit movements. This proposal seeks to examine the activity of neural elements in these networks and the consequence on behavior during a perturbation that alters the balance between the two. The focus is specifically on the superior colliculus, whose rostral pole is involved in preserving fixation and caudal region is essential fo generating saccades. The perturbation of choice is to induce a blink by delivering an air-puff to an eye as subjects perform various oculomotor tasks. Blinks have been shown to compromise the integrity of the saccadic inhibition network at the level of the pons, and if the blink is triggered after presentation of the saccade target (and permission to initiate the movement), the goal-directed movement accompanies the blink at a reduced latency. Specific Aim 1 examines the effects of a blink on the fixation and saccade generation networks in the superior colliculus. It specifically tests the hypothesis that blinks suppress activity in the fixation network (rostral region) and increases the excitability of the saccade generation network (caudal region). Specific Aim 2 examines whether the underlying neural activity at the time of prematurely triggered saccades encodes premotor information. It will specifically test the threshold principle of the motor preparation hypothesis and whether spatial attention and motor preparation can be dissociated. We anticipate that the combination of behavioral and neurophysiological approaches will provide insights into neural mechanisms that are altered in neuropsychiatric disorders (e.g., ADHD, schizophrenia) characterized by an inability to suppress reflexive movements.