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.

项目概要 在美国，听力损失是一种普遍存在的感觉病症，影响着超过 3000 万人。一个 很大一部分耳聋是由于感音神经性听力损失造成的，这通常涉及听力损失 传入神经纤维，将听觉信息从内耳的机械敏感毛细胞传递到外耳 脑。生理听力的恢复需要传入感觉纤维的再生 耳蜗上皮细胞，然后是适当的毛细胞目标的神经支配。神经再生 由于内耳的可及性有限，因此缺乏对人类和其他哺乳动物模型的研究。这 斑马鱼侧线系统，由表面流体流动检测毛细胞和传入神经纤维组成， 提供了一种简单易行的神经再生模型。在这个模型中，可能存在各种旁分泌， 近分泌和神经元自主信号机制协调工作以指导轴突寻路和 目标选择。该提案的目标 1 将确定目标感官表达的分子线索 毛细胞通过再生侧线传入轴突来引导神经支配。横切后 斑马鱼的侧线神经、毛细胞将在多个时间点被分离。在这些毛细胞中， 可用于吸引轴突生长的规范和非规范分子线索的表达变化 视锥细胞将通过转录组测序进行量化。目标 2 将研究神经元偏差 发育相关毛细胞群的神经支配重新支配。尽管研究表明神经元保留 他们对原始毛细胞目标有记忆，但这种记忆是如何建立或维持的尚不清楚。一个 转基因成像技术将用于标记和追踪再生轴突的克隆群体 横断侧线神经。据推测，神经元更喜欢重新支配由毛细胞产生的毛细胞。 开发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 再生神经以允许单个传入纤维进入其目标器官。通过成像 带有荧光标记雪旺细胞和胶原蛋白的转基因鱼，雪旺细胞会出现变化 束和上皮基底膜允许单个轴突进入斑马鱼神经丘， 其中包含目标毛细胞。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，允许再生轴突分支通过 脱离主神经束。这些研究将共同​​阐明控制传入神经的机制 毛细胞的再生和神经支配，这可能为恢复听力提供见解 聋哑的人类耳蜗。这些研究将在 A. J. Hudspeth 博士的直接指导下进行 洛克菲勒大学以及三机构医学博士-博士项目的支持环境 纽约市。