Cortical and Sub-cortical Contributions to Bimanual Coordination

皮质和皮质下对双手协调的贡献

• 批准号: BB/G002355/1
• 负责人: Stuart Baker
• 金额: $ 79.73万
• 依托单位: Newcastle University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FG002355%2F1
• 关键词: Cortical; Sub; cortical; Contributions; Bimanual

Many everyday actions require coordinated movement of the two hands. For example, when we unscrew the top of a bottle, one hand exerts torques on the cap whilst the other holds the bottle steady. The holding hand must precisely compensate for the torques imposed by the other hand, otherwise the bottle will slip. In this project, we will investigate the neural systems underlying bimanual coordination. Macaque monkeys will be trained on two tasks, involving squeezing levers between finger and thumb with both hands. In one task, forces exerted by one hand must be compensated by the other - similar to the bottle opening example above. In the other task, the relative timing of the two hands must be precisely controlled. We expect that in the first task, neural systems controlling each hand will exchange information about movement parameters (level of force); in the second, they will exchange timing information. We will then make recordings from multiple regions of the nervous system which could be involved in bimanual coordination. In the cerebral cortex, we will focus on two motor regions. Rather than just recording any cells, we will search specifically for neurons which send projections to the other side of the brain - either to the cortex, or to the basal ganglia. We will identify these cells using a stimulation paradigm, and then observe their firing during the trained bimanual movements. This is a powerful approach, as it allows us to place the natural activity of the neurons during tasks of interest in the context of their known anatomical connections with the opposite side. Secondly, we will record from the cerebellum and reticular formation. Both regions are important for bimanual control. The reticular formation on one side of the brain sends projections to both sides of the spinal cord. We have recently shown that the cerebellum can also influence movements bilaterally. Recording from these regions will indicate their relative importance for the two types of bimanual coordination (parametric vs timing) represented by the trained tasks. Finally, we will record from the region of the spinal cord believed to contain 'commisural interneurones'. These cells send axonal projections to the other side of the cord, and provide a spinal pathway by which information could be exchanged for the coordination of bimanual movement. The spinal recordings in awake behaving monkeys will be supplemented by recordings in terminally anaesthetised monkeys. In these experiments, we will record from the spinal cells which control muscles (motoneurons), and measure the inputs from the other side of the cord via presumed commissural interneuron pathways. This will provide detailed information about the importance of this system in the control of the primate hand: until now, commissural interneurons have been investigated mainly in the part of the cat spinal cord which controls the hind limb. This project will provide important new information on how the brain coordinates movements bimanually. Most previous studies in this field have used behavioural observations in humans. Previous work in trained monkeys has investigated unidentified neurons in the cerebral cortex. This project will record neural activity directly, during representative bimanual tasks. The subset of cortical neurons which project across the midline will be specifically targeted. It will also record from important sub-cortical and spinal centres. These are often ignored in discussions of bimanual control, mainly because of their inaccessibility to non-invasive methods in man. Yet the motor system is a distributed system, and all movements result from the coordinated action of multiple interconnected structures. In bimanual control, as in other areas of motor control, we will not understand how the brain achieves the exquisite performance which we all take for granted unless we investigate all the component systems.

许多日常动作都需要双手的协调动作。例如，当我们拧开瓶盖时，一只手在瓶盖上施加扭矩，而另一只手则保持瓶子稳定。拿瓶子的那只手必须精确地补偿另一只手施加的扭矩，否则瓶子会打滑。在这个项目中，我们将研究双手协调背后的神经系统。猕猴将接受两项任务的训练，包括用双手在手指和拇指之间挤压杠杆。在一项任务中，一只手施加的力必须由另一只手补偿-类似于上面的瓶子打开例子。在另一项任务中，必须精确控制两只手的相对时间。我们预计，在第一个任务中，控制每只手的神经系统将交换有关运动参数（力的大小）的信息;在第二个任务中，它们将交换时间信息。然后，我们将从神经系统的多个区域进行记录，这些区域可能涉及双手协调。在大脑皮层中，我们将重点关注两个运动区域。我们不只是记录任何细胞，而是专门寻找将投射发送到大脑另一侧的神经元-要么发送到皮层，要么发送到基底神经节。我们将使用刺激范例识别这些细胞，然后观察它们在训练双手动作期间的放电。这是一种强大的方法，因为它允许我们将神经元在感兴趣的任务中的自然活动置于它们与对侧的已知解剖学连接的背景下。其次，我们将记录从小脑和网状结构。这两个区域对双手控制都很重要。大脑一侧的网状结构将投射发送到脊髓的两侧。我们最近发现小脑也可以影响双侧运动。来自这些区域的记录将表明它们对于训练任务所代表的两种类型的双手协调（参数与时间）的相对重要性。最后，我们将记录被认为含有“连合间神经元”的脊髓区域。这些细胞将轴突投射发送到脊髓的另一侧，并提供一个脊髓通路，通过该通路可以交换信息以协调双手运动。清醒行为猴的脊髓记录将通过终末麻醉猴的记录进行补充。在这些实验中，我们将记录控制肌肉（运动神经元）的脊髓细胞，并通过假定的连合中间神经元通路测量来自脊髓另一侧的输入。这将提供详细的信息，这个系统的重要性，在控制灵长类动物的手：到现在为止，连合interneurons主要是在猫的脊髓控制后肢的一部分进行了研究。这个项目将提供关于大脑如何协调双手动作的重要新信息。这一领域以前的大多数研究都使用了人类的行为观察。以前在训练过的猴子身上的工作已经调查了大脑皮层中未识别的神经元。这个项目将直接记录神经活动，在代表性的双手任务。将特异性靶向投射穿过中线的皮质神经元的子集。它还将记录重要的皮层下和脊髓中心。在讨论双手控制时，这些通常被忽略，主要是因为它们在人类中无法使用非侵入性方法。然而，运动系统是一个分布式系统，所有运动都是多个相互连接的结构协调作用的结果。在双手控制中，就像在其他运动控制领域一样，除非我们研究所有的组成系统，否则我们将无法理解大脑是如何实现我们都认为理所当然的精致性能的。

项目成果

Lack of evidence for direct corticospinal contributions to control of the ipsilateral forelimb in monkey.

• DOI: 10.1523/jneurosci.0257-11.2011
• 发表时间: 2011-08-03
• 期刊: The Journal of neuroscience : the official journal of the Society for Neuroscience
• 作者: Soteropoulos DS;Edgley SA;Baker SN
• 通讯作者: Baker SN

Spinal Commissural Connections to Motoneurons Controlling the Primate Hand and Wrist

脊髓连合与控制灵长类动物手和手腕的运动神经元的连接

• DOI: 10.1523/jneurosci.0269-13.2013
• 发表时间: 2013
• 期刊: Journal of Neuroscience
• 影响因子: 5.3
• 作者: Soteropoulos D