Volitional control of neural activity in the oculomotor system

动眼系统神经活动的意志控制

• 批准号: 9901948
• 负责人: Neeraj J Gandhi
• 金额: $ 22.62万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9901948
• 关键词: Action Potentials; Algorithms; Animals; Attention deficit hyperactivity disorder; Auditory; Biomimetics; Brain; Brain Stem; Cells; Cognitive; Data; Development; Dimensions; Disease; Elements; Environment; Exhibits; Eye Movements; Generations; Gold; Individual; Knowledge; Lead; Learning; Mediating; Modeling; Monkeys; Motor; Movement; Neurons; Neurosciences; Parkinson Disease; Patients; Pattern; Population; Process; Rewards; Rodent; Saccades; Schizophrenia; Sensory; Structure; System; Testing; Time; Training; Visual; Volition; Work; base; brain computer interface; design; dynamic system; gaze; improved; innovation; insight; motor control; neural prosthesis; neuroregulation; oculomotor; preservation; relating to nervous system; response; sensory input; statistics; superior colliculus Corpora quadrigemina; visual motor; visual stimulus

PROJECT SUMMARY Sensorimotor transformations are mediated by premotor brain networks where individual neurons represent sensory, cognitive, and movement-related information. In the superior colliculus (SC), a central hub for producing visually-guided saccadic eye movements, many neurons emit a burst of action potentials both in response to a visual stimulus and when generating an eye movement command. These so-called visuomotor neurons project to the brainstem burst generator that produces the saccade. Thus, this downstream element is challenged to differentiate between the incoming “visual” and “motor” bursts. Multiple mechanisms have been proposed to account for movement generation. The “fixed threshold” hypothesis posits that a saccade is produced once the firing rate of either an individual neuron or across a population crosses a threshold, which only happens during the motor burst. Existing data, however, indicate that a simple thresholding mechanism is likely not sufficient and requires consideration of other frameworks. The “optimal subspace” hypothesis uses a dynamical systems approach to propose that a movement is generated when the population activity enters or resides within a particular region of state space. This implies that the state space representations of SC visual and motor bursts are dissociable. The “temporal stability” hypothesis states that a movement is generated when bursting activity across a population of neurons preserves consistent temporal structure for a period of time. Indeed, the stability of SC population activity is reduced during a visual response (“unstable” temporal structure) and increased during an eye movement (“stable” temporal structure). We seek a framework that reconciles these models. Our central hypothesis is that SC population activity is decoded as a movement command when it both exhibits high temporal structure and resides within an optimal subspace. Our specific aim is to employ a closed-loop brain-computer interface in which monkeys are trained to control an auditory cursor by volitionally modulating the activity pattern across multiple SC neurons to lie within a visual or motor subspace and to be temporally stable or unstable. We will first test the optimal subspace and temporal stability frameworks individually before pitting the two against each other in a 2x2 design. Examining the trials in which an eye movement is observed will reveal the patterns used by population activity to represent a movement command. We predict that the animals will be able to modulate population activity along both visual-motor subspace and stable-unstable dimensions, but that the likelihood of movement generation will be the highest when the population activity is both stable and in the optimal subspace.

项目概要 感觉运动转换由运动前脑网络介导，其中单个神经元代表 感觉、认知和运动相关的信息。上丘 (SC) 是大脑的中枢 产生视觉引导的眼跳运动，许多神经元在 对视觉刺激的响应以及生成眼球运动命令时的响应。这些所谓的视觉运动 神经元投射到产生眼跳的脑干爆发发生器。因此，该下游元件是 面临的挑战是区分传入的“视觉”和“运动”突发。多种机制已出台 建议考虑运动的产生。 “固定阈值”假说假设眼跳是 一旦单个神经元或整个群体的放电率超过阈值，就会产生 仅发生在电机突发期间。然而，现有数据表明，一个简单的阈值机制是 可能还不够，需要考虑其他框架。 “最优子空间”假设使用 动力系统方法提出当人口活动进入或 驻留在状态空间的特定区域内。这意味着 SC 视觉的状态空间表示 和运动爆发是可分离的。 “时间稳定性”假说指出运动的产生 当一群神经元的突发活动在一段时间内保持一致的时间结构时 时间。事实上，SC 群体活动的稳定性在视觉反应期间会降低（“不稳定”的时间 结构）并在眼球运动期间增加（“稳定”时间结构）。我们寻求一个框架 协调这些模型。我们的中心假设是 SC 人口活动被解码为一种运动 当它既表现出高时间结构又驻留在最佳子空间内时，它就会发出命令。我们的具体 目的是采用闭环脑机接口，训练猴子控制听觉 通过有意识地调节多个 SC 神经元的活动模式以使其位于视觉或运动范围内 子空间并且暂时稳定或不稳定。我们将首先测试最佳子空间和时间稳定性 在将两者以 2x2 设计相互竞争之前，先单独构建框架。检查其中的试验 观察眼球运动将揭示人口活动用来表示运动的模式 命令。我们预测动物将能够沿着视觉运动调节群体活动 子空间和稳定-不稳定维度，但运动产生的可能性最高 当种群活动既稳定又处于最优子空间时。