Mechanisms of sensory hair cell reinnervation following lateral line cranial nerve damage in Danio rerio

斑马鱼侧线脑神经损伤后感觉毛细胞神经支配的机制

• 批准号: 10749736
• 负责人: Rohan Roy
• 金额: $ 5.27万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10749736
• 关键词: Acoustic Nerve; Affect; Auditory; Axon; Axotomy; Basement membrane; Brain; Brain-Derived Neurotrophic Factor; Cell membrane; Cell surface; Cells; Cochlea; Collagen; Confocal Microscopy; Cranial Nerves; Cues; Data; Development; Doctor of Philosophy; Epithelium; Extracellular Matrix; Fiber; Fishes; Fluorescence-Activated Cell Sorting; Ganglia; Genes; Genomics; Goals; Growth Cones; Hair Cells; Hearing; Human; Image; Imaging Techniques; Individual; Inner Hair Cells; Institution; Label; Labyrinth; Larva; Mammals; Mechanics; Memory; Mentorship; Microscopy; Modeling; Molecular; Natural regeneration; Nerve; Nerve Fibers; Nerve Regeneration; Nervous System; Neurites; Neurons; New York City; Olfactory Nerve; Organ; Organism; Pathology; Persons; Physical environment; Physiological; Population; Positioning Attribute; Publishing; Regenerative capacity; Regenerative research; Research Personnel; Resolution; Reverse Transcription; Role; Schwann Cells; Sensorineural Hearing Loss; Sensory; Sensory Hair; Signal Transduction; Structure; Synapses; System; Testing; Traction; Transgenes; Transgenic Organisms; United States; Universities; Zebrafish; afferent nerve; analog; axon growth; axon regeneration; axonal pathfinding; cell behavior; confocal imaging; deaf; deafness; experimental study; fluid flow; hearing impairment; hearing restoration; in vivo; insight; lateral line; mechanical signal; model organism; nerve damage; neuromast; neurotrophic factor; paracrine; prevent; programs; reinnervation; restoration; sensory mechanism; sound; supportive environment; transcriptome sequencing

PROJECT SUMMARY Loss of hearing is a prevalent sensory pathology in the United States that affects over 30 million people. A significant proportion of deafness is attributed to sensorineural hearing loss, which often involves the damage of afferent nerve fibers which relay auditory information from the mechanosensitive hair cells of the inner ear to the brain. The restoration of physiologic hearing would require the regeneration of afferent fibers into the sensory epithelium of the cochlea, followed by the reinnervation of appropriate hair cell targets. Nerve regeneration studies in humans and other mammalian models are lacking due to the limited accessibility of the inner ear. The zebrafish lateral line system, composed of superficial fluid-flow detecting hair cells and afferent nerve fibers, offers a simple and accessible model of nerve regeneration. In this model, there are likely various paracrine, juxtacrine, and neuron-autonomous signaling mechanisms working in coordination to guide axon pathfinding and target selection. Aim 1 of this proposal will determine the molecular cues expressed by target sensory hair cells to guide reinnervation by regenerating afferent axons of the lateral line. Following transection of the lateral line nerve, hair cells from the zebrafish will be isolated at multiple timepoints. In these hair cells, the expression changes of canonical and non-canonical molecular cues that may be used to attract axonal growth cones will be quantified through transcriptome sequencing. Aim 2 will investigate the neuronal bias for reinnervation of developmentally related hair cell populations. Although studies suggest that neurons retain a memory for their original hair cell targets, how this memory is established or maintained is unknown. A transgenic imaging technique will be used to label and trace clonal populations of regenerating axons following transection of the lateral line nerve. It is hypothesized that neurons prefer reinnervating hair cells that arose from a shared sensory placode during development. Aim 3 will reveal changes in the local physical environment of the regenerating nerve to allow entry of individual afferent fibers into their target organ. By imaging transgenic fish with fluorescently labeled Schwann cells and collagen, changes will be shown in Schwann cell tracts and the epithelial basement membrane to permit entry of individual axons into the zebrafish neuromast, which contains target hair cells. It is hypothesized that physical gaps form in Schwann cell and basement membrane layers in close proximity to denervated hair cells to allow passage of regenerating axons branching off the main nerve bundle. Together, these studies will elucidate the mechanisms governing afferent nerve regeneration and the reinnervation of hair cells, which may provide insight towards restoring hearing in the deafened human cochlea. These studies will be carried out under the direct mentorship of Dr. A. J. Hudspeth at The Rockefeller University and within the supportive environment of the Tri-Institutional MD-PhD Program in New York City.

项目摘要 听力损失是美国一种普遍的感觉病理学，影响超过3000万人。一 耳聋的很大一部分是由于感觉神经性听力损失，这往往涉及损害的 传入神经纤维，其将听觉信息从内耳的机械敏感毛细胞传递到 个脑袋生理性听力的恢复需要传入纤维的再生进入感觉神经系统。 耳蜗上皮细胞，然后是适当的毛细胞靶点的神经再支配。神经再生 由于内耳的可及性有限，因此缺乏在人类和其它哺乳动物模型中的研究。的 斑马鱼侧线系统，由表层液流检测毛细胞和传入神经纤维组成， 提供了一个简单易行的神经再生模型。在这个模型中，可能有各种旁分泌， 神经元自主信号传导机制协调工作，指导轴突寻路， 目标选择本建议的目的1将确定目标感觉表达的分子线索， 毛细胞通过再生侧线的传入轴突来引导神经再支配。横断后， 在多个时间点分离来自斑马鱼的侧线神经、毛细胞。在这些毛细胞中， 可能用于吸引轴突生长的典型和非典型分子线索的表达变化 通过转录组测序对锥细胞进行定量。目的2将研究神经元的偏见， 发育相关的毛细胞群的神经再支配。尽管研究表明， 对于它们最初的毛细胞目标的记忆，这种记忆是如何建立或维持的是未知的。一 转基因成像技术将用于标记和追踪再生轴突的克隆群体， 切断侧线神经。据推测，神经元更喜欢重新支配毛细胞， 在发育过程中共享的感觉基板。目标3将揭示当地物理环境的变化 以允许单个传入纤维进入它们的靶器官。通过成像 荧光标记雪旺细胞和胶原蛋白的转基因鱼，将显示雪旺细胞的变化 纤维束和上皮基底膜以允许单个轴突进入斑马鱼神经肥大， 其包含靶毛细胞。假设雪旺细胞和基底中形成物理间隙 膜层靠近去神经毛细胞，以允许再生轴突分支通过 从主神经束中分离出来总之，这些研究将阐明传入神经的机制 再生和毛细胞的神经再支配，这可能会提供对恢复听力的见解， 使人耳蜗萎缩。这些研究将在A博士的直接指导下进行。J. Hudspeth在 洛克菲勒大学和在三机构的MD-PhD计划的支持性环境中， 纽约市。