Somatosensory Cortical Influences on Subcortical Processing

描述(申请人提供)：使用躯体感觉系统作为模型系统，我们计划将神经元示踪剂注入双侧大鼠感觉运动皮质，以测试双侧纹状体和桥脑皮质重叠最大的假设，该投射来自代表双侧协调的身体近端部分的MI部位。在猫身上，我们将向运动和躯体感觉皮质注入神经元示踪剂，以检验来自SI和SII的桥脑皮质投射比皮质纹状体投射能够实现更多整合的假设。在这个项目的后半部分，我们将同时记录躯体感觉皮质中的多个神经元以及新纹状体和脑桥中的神经元。我们将检验这一假设，即新纹状体神经元主要当它们从躯体感觉皮质中相关的(即相互连接的)皮质区域接收同步输入时放电。我们还将测试这一假设，即刺激诱导的神经元反应与脑桥的躯体感觉反应比新纹状体的反应更密切相关。 公共卫生相关性：大量证据表明，基底节和桥小脑系统负责感觉运动整合和相关的认知过程。通过将解剖追踪方法与感觉刺激相结合，我们将阐明介导感觉加工的回路机制，并将对这些回路处理认知信息的操作获得有价值的见解。基底节和桥小脑系统中的神经回路与一些神经系统疾病有关，包括帕金森氏病、亨廷顿舞蹈病、抽动综合征和其他感觉运动问题，这一事实突显了这项工作的潜在临床重要性。

DESCRIPTION (provided by applicant): Using the somatosensory system as a model system, we plan to inject neuronal tracers bilaterally into rat sensorimotor cortex to test the hypothesis that bilateral corticostriatal and corticopontine overlap is greatest for projections from MI sites representing proximal body parts that are bilaterally coordinated. In cats, we will inject neuronal tracers into motor and somatosensory cortex to test the hypothesis that corticopontine projections from SI and SII enable more integration than corticostriatal projections. In the last half of this project we will record multiple neurons in somatosensory cortex simultaneously with neurons in the neostriatum and the pons. We will test the hypothesis that neostriatal neurons discharge mainly when they receive synchronous inputs from related (ie., interconnected) cortical areas in somatosensory cortex. We will also test the hypothesis that stimulus-induced neuronal responses somatosensory are more strongly correlated with responses in the pons than in the neostriatum. PUBLIC HEALTH RELEVANCE: Substantial evidence indicates that the basal ganglia and pontocerebellar systems are responsible for sensorimotor integration and related cognitive processes. By using anatomical tracing methods in combination with sensory stimulation, we will elucidate the circuit mechanisms that mediate sensory processing and will gain valuable insights about the operation of these circuits for processing cognitive information. The potential clinical importance of this work is underscored by the fact that the neural circuits in the basal ganglia and pontocerebellar systems have been implicated in several neurologic disorders including Parkinson's disease, Huntington's chorea, Tourette's syndrome, and other sensorimotor problems.