Cortical and subcortical control of saccades

描述（由申请人提供）：快速准确的眼球跳动对视力至关重要。由于现实世界的场景经常挤满了许多物体，因此扫视的一个基本要求是从多个潜在目标域中连续选择单个目标。扫视的目标选择是由大脑皮层和皮层下区域组成的网络来完成的，但我们仍然不太清楚这些区域的活动是如何协调的。本项目研究了上丘（SC）、额叶视野（FEF）和背外侧前额叶皮层（dlPFC）之间的相互作用。SC被认为是从皮层到脑干的眼动指令的通道，但SC活动的扰动不仅影响扫视的执行；它们也会影响眼球运动目标的选择。这就提出了一个关键问题：SC是否只是在向下游传递扫视指令之前的最后选择阶段，或者SC的活动是否影响皮层的扫视决策？为了回答这个问题，我们将同时记录SC和FEF的分离神经元和局部场电位，并应用先进的分析技术来揭示这两个区域之间的相互作用和可能的信息流。接下来，我们将通过暂时使SC中的一部分失活来干扰其活动，并将确定FEF中与选择相关的活动是否以及如何改变。我们还将研究额叶皮层如何影响大脑的选择

DESCRIPTION (provided by applicant): Rapid and accurate saccadic eye movements are crucial for vision. Since real-world scenes are often crowded with many objects, a fundamental requirement for saccades is the serial selection of single targets from a field of multiple potentil targets. Saccade target selection is subserved by a network of cortical and subcortical brain areas, but we still have little idea of how activity across these areas is coordinated. This projec investigates the interactions among the superior colliculus (SC), the frontal eye field (FEF), and the dorsolateral prefrontal cortex (dlPFC). The SC is regarded as the gateway for eye-movement commands from cortex to reach the brainstem, but perturbations in SC activity do not just affect the execution of saccades; they also influence the selection of eye-movement targets. This raises a key question: Does the SC simply act as a final selection stage before transmitting saccade commands downstream, or does SC activity influence saccadic decision-making in cortex? To answer this, we will simultaneously record isolated neurons and local field potentials from SC and FEF, and apply advanced analysis techniques to reveal the interactions and likely flow of information between these two areas. Next, we will perturb activity in the SC by temporarily inactivating a portion of it, and will determine whether and how selection-related activity in FEF is altered. We will also investigate how frontal cortex influences selection in the SC. Specifically, frontal area dlPFC is thought to be particularly important for selection based on abstract rules or internal goals. We will test this idea and investigate dlPFC's influence on the SC by analyzing simultaneously-recorded activity in the two areas during performance of rule-governed and salience-based selection tasks. Finally, to test for a causal link with dlPFC, we will record behavior and SC activity while dlPFC is temporarily inactivated. The results will not only provide new information about the functional architecture of saccadic decision-making; they will also lead toward a better understanding of how cortical and subcortical brain areas interact in performance of a cognitive task.