Anatomical Origins of Somatosensory Cortical Magnification in the Star-nosed Mole

星鼻鼹鼠体感皮质放大的解剖学起源

基本信息

批准号：
8875084
负责人：
EVA SAWYER
金额：
$ 2.78万
依托单位：
VANDERBILT UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-07-01 至 2016-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8875084
关键词：
Address Afferent Neurons Anatomy Animals Area Behavioral Body Regions Brain Brain Mapping Brain Stem Cell Nucleus Cells Communities Complex Data Development Disease Electron Microscopy Electrophysiology (science)Epidermis Face Feedback Fingers Hand Health Histocytochemistry Human Hybrids Investigation Knowledge Learning Limb Prosthesis Mammals Maps Measurement Measures Medial Modeling Mole the mammal Neocortex Neuraxis Nose Organ Pathway interactions Pattern Primates Process Relative (related person)Research Personnel Resolution Rodent Role Scanning Electron Microscopy Sensory Side Skin Somatosensory Cortex Somatosensory Disorders Spinal Structure Surface System Tactile Thalamic Nuclei Thalamic structure Tissues Touch sensation Trigeminal System Trigeminal nerve structure Vibrissae analog appendage base density fovea centralis insight nerve supply neural tract new technology receptive field somatosensory therapy development

项目摘要

DESCRIPTION (provided by applicant): In our somatosensory cortex our fingertips have representations that are disproportionally large compared to the skin surface area that is not clearly explained by innervation patterns[1, 2]. The large representations of our fingertips is correlated with higher acuity touch in these regions[3]. Disproportionate cortical representation of sensory surfaces is sometimes termed cortical magnification, but the relative contribution of cortical and subcortical somatosensory areas to this phenomenon has not been addressed. The subcortical specializations of representing these high acuity areas may be underappreciated. This study investigates the subcortical representations of high acuity touch using the star of the star-nosed mole. This animal is the ideal animal in which to study fundamental questions in cortical magnification. The star of the star-nosed mole has many features in common with the hands of primates, such as being a glabrous skin surface, varying in acuity across the skin surface, and cortical over-representation of the highest acuity "fovea" area[4]. The star also has many features in common with the well-studied rodent whisker system, such as being a trigeminal somatosensory specialization and being represented by segmented somatotopic maps in the somatosensory cortex. In rodents these maps are also found in the ascending trigeminal somatosensory pathway in the thalamus and the brainstem. I hypothesize, and have pilot data suggesting, that there will be analogues maps of the star in these nuclei. Once found, the volumes of ray representations can be measured. This study proposes to use electrophysiology, histochemistry, and neural tract tracing to describe and measure the subcortical star representations in this pathway, specifically in the spinal trigeminal complex and the ventral posterior medial nucleus of the thalamus. This will allow us to ask which somatosensory areas contribute to the observed cortical magnification, which may give us insights into the roles of these areas in touch processing. I will also use the new technology of serial block-face electron microscopy to investigate patterns of sensory neuron arborization at the star surface. A better understanding of the fundamental organization of the somatosensory system is vital to the development of treatments for somatosensory disorders and sensory loss.

描述（由申请人提供）：在我们的体感皮质中，我们的指尖具有与皮肤表面积相比不成比例的，而神经表面积并未通过神经化模式清楚地解释[1，2]。在这些区域中，我们指尖的较大表示与更高的敏锐触摸相关[3]。感觉表面的不成比例的皮质表示有时被称为皮质放大倍数，但是尚未解决皮质和皮层体体体积区域对这种现象的相对贡献。代表这些高敏度区域的皮层专业可能会被低估。这项研究研究了使用星条痣的星星的高敏度接触的皮质下表示。这种动物是研究皮质放大倍数基本问题的理想动物。星鼻痣的恒星与灵长类动物的手有许多共同的特征，例如是无毛的皮肤表面，在皮肤表面上的敏锐度变化，皮质的过度代表性最高的敏锐度“ fovea”区域[4]。这颗恒星还具有许多与经过良好研究的啮齿动物晶须系统的共同特征，例如是三叉体的体感专业化，并由体感皮质中的分段体体图表示。在啮齿动物中，这些地图在丘脑和脑干的上升三叉神经体感途径中也发现。我假设并有指示数据表明，这些核中将有恒星的类似图。一旦找到，就可以测量射线表示的体积。这项研究建议使用电生理学，组织化学和神经道追踪来描述和测量该途径中皮层恒星的表示，特别是在脊柱三叉神经复合物和丘脑的腹侧内侧核。这将使我们能够询问哪些体感区域有助于观察到的皮质放大倍数，这可能使我们能够了解这些区域在接触处理中的作用。我还将使用新的串行块面电子显微镜的技术来研究恒星表面的感觉神经元树木的模式。更好地理解体感系统的基本组织对于发展体感疾病和感觉丧失的治疗方法至关重要。