Divergence of Tactile Processing in the Dorsal Column Nuclei

项目摘要 支配皮肤的各种感觉神经元是我们感知一个显著范围的能力的基础。 触觉刺激，并为我们提供了操纵物体，检测威胁和导航我们的能力。 环境尽管我们的触觉至关重要，但我们对接受者如何感知我们的身体知之甚少。 脑干背柱核（DCN）中的神经元整合初级感觉信息，以及 然后，处理过的信息被传送到大脑。解剖追踪研究显示， 重叠的下游目标的DCN，最突出的是丘脑和下丘。作为 我假设，它是来自外周和中枢躯体感觉通路的感觉信息之间的节点， DCN作为差异感觉整合的部位，选择性地调整输出通路， 在环境中。我提出的实验将通过表征调谐特性来解决这一假设 的DCN投射神经元，目标下丘和丘脑，并通过调查如何 通过来自外周感觉神经元和抑制性中间神经元的输入来构建响应。这项工作将 通过将新颖的脑干记录方法与操纵脑干的工具相结合， 初级感觉神经元的活动。在这样做的过程中，我的建议将深入了解DCN如何处理 触觉信息，也可能阐明大脑组织感觉的更一般的机制 信息.此外，对早期躯体感觉处理的基本理解将为以下努力提供信息： 开发神经修复术，并指导治疗躯体感觉改变的临床病例，如 如外周神经损伤后的机械性异常性疼痛或个体表现出的对轻触的超敏反应 患有自闭症

Project Summary The diverse range of sensory neurons that innervate the skin underlie our ability to perceive a remarkable range of tactile stimuli and provide us with the capacity to manipulate objects, detect threats, and navigate our environment. Despite the fundamental importance of our sense of touch, little is known about how recipient neurons in the dorsal column nuclei (DCN) of the brainstem integrate primary sensory information, and how processed information is then transmitted to the brain. Anatomical tracing studies have revealed multiple, non- overlapping downstream targets of the DCN, the most prominent being the thalamus and inferior colliculus. As the node between sensory information from the periphery and central somatosensory pathways, I hypothesize that the DCN functions as a site of differential sensory integration to selectively tune output pathways to features in the environment. My proposed experiments will address this hypothesis by characterizing the tuning properties of DCN projection neurons that target the inferior colliculus and the thalamus, and by investigating how responses are constructed by inputs from peripheral sensory neurons and inhibitory interneurons. This work will overcome barriers in the field by combining novel brainstem recording methods with tools to manipulate the activity of primary sensory neurons. In doing so, my proposal will yield insights into how the DCN processes tactile information, and may also illuminate more general mechanisms by which the brain organizes sensory information. Additionally, a fundamental understanding of early somatosensory processing will inform efforts to develop neural prosthetics, as well as guide efforts to treat clinical cases where somatosensation is altered, such as mechanical allodynia after peripheral nerve injury or hypersensitivity to light touch exhibited by individuals with autism.