Neural basis of limb selection in unimanual reaching

单手抓取肢体选择的神经基础

基本信息

批准号：
10446925
负责人：
ERIC F MOOSHAGIAN
金额：
$ 43.61万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-04-15 至 2027-02-28
项目状态：
未结题

项目摘要

Abstract The central goal of this proposal is to understand the neural systems subserving the decision to use the left or right hand1 – a simple choice that is central to our daily functions. Here we focus on parietal mechanisms of limb selection. Despite it being one of the most common decisions faced in everyday behavior, a largely neglected aspect of decision making is deciding which hand to use to achieve a goal. For instance, when deciding which hand to use to flip a light switch upon entering a room, the choice is influenced by many factors. These factors include what each hand is already doing (e.g, holding a phone), proximity of each hand to the switch, and future goals (e.g., desire to subsequently pick up an object with a particular hand). Our long- term goals are to elucidate the fundamental mechanisms of limb selection and movement coordination. Because limb selection is present in most behaviors, this work will provide insights broadly applicable to motor control. The posterior parietal cortex (PPC) is known to be involved in the planning and control of actions in an effector-specific manner. An emerging concept is that the same PPC regions that are involved in movement preparation and control also participate in action selection. We recently demonstrated that a parietal region known to contribute to the planning of arm movements and dubbed “the parietal reach region” (PRR), codes the spatial targets for reaches with the contralateral arm but receives information about the ipsilateral arm from the opposite hemisphere. PRR has also been implicated in the decision to reach versus saccade to a spatial target. In our first aim, we characterize limb selection behavior and determine the factors that drive limb selection. In our second aim we test the hypothesis that PRR is involved in limb selection during unimanual reaching. Next, we examine interhemispheric communication as a function of limb choice. Finally, we use reversible inactivation of the callosal fibers connecting PRR in each hemisphere to determine the role of interhemispheric competition in determining which limb to use. Collectively, these studies will have a broad impact on the field by illuminating the roles of PPC and callosal connections in a fundamental choice motor behavior. The results will lay the foundation for future studies that probe the larger bilateral frontoparietal network involved in movement control. The work may inform rehabilitation approaches for patients with neurological disorders including stroke and traumatic brain injuries in whom limb use is affected. 1 We will use the terms limb, arm, and hand interchangeably.

摘要该提案的中心目标是了解支持决策的神经系统使用左手或右手1——这是我们日常功能的核心的简单选择。这里我们重点关注顶叶。尽管这是日常行为中最常见的决定之一，决策过程中一个被忽视的方面是决定使用哪只手来实现目标。当决定进入房间时用哪只手打开电灯开关时，选择会受到许多因素的影响这些因素包括每只手已经在做什么（例如，拿着电话）、每只手的距离。到开关，以及未来的目标（例如，希望随后用特定的手拿起一个物体）。长期目标是阐明肢体选择和运动协调的基本机制。由于肢体选择存在于大多数行为中，这项工作将提供广泛适用于运动的见解众所周知，后顶叶皮层（PPC）参与行动的规划和控制。一个新兴的概念是参与运动的相同 PPC 区域。我们最近证明了顶叶区域也参与了准备和控制。已知有助于规划手臂运动并被称为“顶叶区域”（PRR），代码空间目标与对侧手臂接触，但接收有关同侧手臂的信息另一半球的 PRR 也与到达或扫视空间的决定有关。在我们的第一个目标中，我们描述肢体选择行为并确定驱动肢体的因素。在我们的第二个目标中，我们测试了 PRR 参与单手动肢体选择的假设。接下来，我们检查半球间的交流作为肢体选择的函数。连接每个半球 PRR 的胼胝体纤维的可逆失活以确定总的来说，这些研究将在决定使用哪个肢体时进行大脑半球间的竞争。通过阐明 PPC 和胼胝体连接在基本选择运动中的作用来对该领域产生影响研究结果将为未来探索更大的双侧额顶叶的研究奠定基础。这项工作可能会为患有运动控制的患者提供康复方法。神经系统疾病，包括影响肢体使用的中风和脑外伤。 1 我们将交替使用术语“肢体”、“手臂”和“手”。