The neural control of disjunctive saccades

分离性眼跳的神经控制

• 批准号: 155118-2007
• 负责人: Cullen, Kathleen
• 金额: $ 3.06万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=366474
• 关键词: neural; control; disjunctive; saccades

We naturally reorient our eyes to targets of interest located at different eccentricities and depths. However how the brain ensures the precise control of binocular positioning remains highly controversial.Objective: The main objective of this study is to understand how the brain generates disjunctive saccades. In our recent work, we have shown that the neurons of the brainstem saccadic generator, which are typically considered a source of purely conjugate premotor drive, in fact provide temporally appropriate vergence information to drive eye motion during disjunctive saccades. In the present proposal, we will take this work to the next stage and identify the source of the vergence-related signals of premotor saccadic neurons. One obvious candidate is the superior colliculus, which receives inputs from disparity sensitive cortical regions such as the frontal eye fields. Additional vergence inputs to premotor saccadic neurons could come from the cerebellum and/or its deep nuclei. In particular, the oculomotor vermis and caudal fastigial nucleus have important projections to the premotor saccadic region and contain neurons whose discharges are related to saccades. Finally, neurons in the midbrain such as vergence-velocity neurons, which have only been characterized during smooth vergence, may also play a role in driving disjunctive saccades by means of their direct projections to the extraocular motoneurons. Each of these possibilities will be systematically explored.Scientific Approach: The activity of single neurons in alert behaving monkeys will be quantified during saccade-vergence interactions in alert behaving monkeys. System identification techniques developed in our laboratory will be used to describe the discharge dynamics of neurons during conjugate and disjunctive movements. The resultant data will be interpreted in the context of current models of the oculomotor system.Experimental Significance: Results will be used to generate theoretical models of the networks that control saccade-facilitated vergence.  These models will, in turn, provide a foundation that can be used to understand how the brain coordinates the movement of multiple muscles to generate more complex voluntary movements.

我们自然地将眼睛重新定位到位于不同偏心率和深度的感兴趣目标。然而大脑如何确保双眼定位的精确控制仍然存在很大争议。 目的：本研究的主要目的是了解大脑如何产生分离性眼跳。在我们最近的工作中，我们表明，脑干扫视发生器的神经元通常被认为是纯粹共轭运动前驱动的来源，实际上提供了时间上适当的聚散信息来驱动分离扫视期间的眼睛运动。在目前的提案中，我们将把这项工作推进到下一阶段，并确定运动前扫视神经元的聚散相关信号的来源。一个明显的候选者是上丘，它接收来自视差敏感皮层区域（例如额眼区）的输入。运动前扫视神经元的额外聚散输入可能来自小脑和/或其深部核团。特别是，动眼蚓部和尾顶核对运动前扫视区有重要的投射，并且包含与扫视相关的放电的神经元。最后，中脑中的神经元，例如仅在平滑聚散期间表征的聚散速度神经元，也可能通过直接投射到眼外运动神经元而在驱动分离性扫视中发挥作用。这些可能性中的每一种都将被系统地探索。科学方法：在警觉行为猴子的扫视-聚散相互作用过程中，将量化警觉行为猴子中单个神经元的活动。我们实验室开发的系统识别技术将用于描述共轭和分离运动期间神经元的放电动力学。由此产生的数据将在当前动眼神经系统模型的背景下进行解释。实验意义：结果将用于生成控制扫视促进的聚散度的网络的理论模型。  反过来，这些模型将为理解大脑如何协调多个肌肉的运动以产生更复杂的随意运动提供基础。