Development of the Gustatory Solitary Nucleus

味觉孤核的发育

• 批准号: 8020949
• 负责人: Robert M Bradley
• 金额: $ 31.2万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8020949
• 关键词: Acute; Address; Adult; Alcohol consumption; Animals; Anterior; Antibodies; Axon; Behavior; Biological; Birth; Brain Stem; Bromodeoxyuridine; Cell Cycle; Cell Nucleus; Cells; Cellular Structures; Characteristics; Data; Development; Diet; Dorsal; Electroporation; Embryo; Embryonic Development; Erinaceidae; Esthesia; Facial nerve structure; Feeding behaviors; Foundations; Fourth ventricle structure; Glossopharyngeal nerve structure; Goals; Health; Immunofluorescence Immunologic; Immunohistochemistry; In Vitro; Intake; Investigation; Knowledge; Lateral; Length; Life; Location; Maps; Measures; Medial; Molecular; Morphology; Nerve; Neuraxis; Neuroglia; Neurons; Neurophysiology - biologic function; Nucleus solitarius; Nutrient; Oligodendroglia; Pathway interactions; Pattern; Pattern Formation; Peripheral; Pharmaceutical Preparations; Preparation; Process; Proliferating; Property; Quality of life; Rattus; Regulation; Research; Rodent; Role; Sensory; Signaling Molecule; Slice; Staging; Synapses; System; Taste Buds; Taste Perception; Testing; Time; Tongue; Tube; Undifferentiated; Vertebrates; Western Blotting; Whole-Cell Recordings; Work; feeding; knock-down; mature animal; migration; nerve stem cell; nerve supply; nervous system development; neural circuit; neural patterning; neurodevelopment; neuron development; neurophysiology; postnatal; receptor; reconstruction; research study; smoothened signaling pathway; synaptogenesis; tongue papilla

DESCRIPTION (provided by applicant): The rostral portion of the nucleus of the solitary tract (rNST) in the brainstem is the first central taste relay. The rNST receives primary afferent projections from facial and glossopharyngeal nerves, which innervate lingual taste buds and papillae and terminate centrally in a topography that reflects peripheral organization. The time course for and molecular factors involved in proliferation and differentiation of rNST cells are not well understood. Given the importance of an organized taste system for proper function, the long-term objective is to determine how the rNST is established in embryonic rat. The proposed research aims are to determine: the development of solitary tract (ST) projections; the developmental time course of proliferation and differentiation of cell components comprising the rNST; the development of biophysical properties and synapses of rNST neurons; specific molecular factors present in relation to rNST development; and, to manipulate the expression of these factors to determine effects on rNST development. Immunofluorescence will be used to identify the time course for development of neurons and glia that compose the rNST in staged embryos. An in vitro brainstem slice preparation will be used to determine development of neuron function. Immunohistochemical and Western blot approaches will be used to identify the expression of Sonic hedgehog (Shh) signaling factors potentially important for proliferation and differentiation in the NST, and cell cycle regulators across developmental stages. Finally, an explant culture system will be used to isolate the brainstem and manipulate in vitro Shh signaling molecules localized to the rNST and surround. The working hypotheses are that during embryonic development, neural precursors migrate from the fourth ventricle and differentiate to form the earliest rNST, where neurons differentiate before glia; that rNST neurons are functional, but with changing properties, in the embryo; and, that Shh signaling regulates the timing of proliferation and differentiation of rNST neural precursors and emerging neurophysiological function in rNST. Results of these experiments will provide an understanding of the early establishment, organization and function of the rNST and will demonstrate possible molecular pathways involved in that development. This will provide an important foundation for understanding the formation of the primary afferent relay of the gustatory system and lay the groundwork for understanding the demonstrated plasticity that occurs in this relay when environmental manipulations take place during embryogenesis. Furthermore, the proposal addresses essential questions in the process of neural patterning in the CNS. PUBLIC HEALTH RELEVANCE: Taste sensation, which guides nutritive choices and ingestive behaviors of all vertebrates, is transduced by peripheral receptors and conveyed directly to the brainstem where it is integrated with other sensory inputs in the rostral nucleus of the solitary tract (rNST). Knowledge of initial development of neurons and glia within the solitary nucleus that receive this sensory input will contribute to a more complete understanding of how taste information is integrated in the central nervous system to inform diet choices, a behavior important to sustain life. Determining how and when function emerges in rNST and is regulated at a molecular level will be essential in understanding plasticity of the taste system. Because animals have to feed at birth, the rNST must be functional to guide initial nutrient intake. It is therefore important to characterize factors controlling normal development of rNST to understand how maternal diet, alcohol consumption and drugs can influence neural development and synaptogenesis of the rNST.

描述（由申请人提供）：脑干中孤立区（RNST）核的延髓部分是第一个中央味道继电器。 RNST从面部和舌咽神经中获得了主要传入的预测，这些神经支配了舌味芽和乳头，并在反映外围组织的地形中集中终止。尚不清楚与RNST细胞增殖和分化有关的时间过程和分子因素。鉴于有组织的味觉系统对适当功能的重要性，长期目标是确定在胚胎大鼠中如何建立RN。拟议的研究目的是确定：孤立区（ST）预测的发展；构成RN的细胞成分增殖和分化的发育时间过程； RNS神经元的生物物理特性和突触的发展；与第一个发展有关的特定分子因素；并且，操纵这些因素的表达以确定对RN的影响的影响。免疫荧光将用于确定在分阶段胚胎中构成RN的神经元和神经胶质的时间过程。体外脑干切片制剂将用于确定神经元功能的发展。免疫组织化学和蛋白质印迹方法将用于识别Sonic刺猬（SHH）信号传导因子的表达，这对于NST的增殖和分化可能很重要，以及跨发育阶段的细胞周期调节剂。最后，将使用epplant培养系统来隔离脑干并在体外SHH信号分子中操纵位于RNST和ARNCRANT的体外SHH信号分子。工作假设是，在胚胎发育过程中，神经前体从第四个心室迁移，并分化为最早的rn，神经元在神经元之前进行了区分。第一个神经元在胚胎中起作用，但特性变化。 SHH信号传导调节了第一个神经前体的增殖和分化的时机以及RNST中新兴的神经生理功能。这些实验的结果将提供对RNST的早期建立，组织和功能的理解，并将证明该开发中可能涉及的分子途径。这将为理解阵阵系统的主要传入继电器的形成，并为理解在胚胎发生过程中发生环境操作时发生的可塑性奠定重要基础。此外，该提案在中枢神经系统中的神经模式过程中解决了基本问题。公共卫生相关性：味觉引导所有脊椎动物的营养选择和摄入行为，被外围受体转导，并直接传达到脑干中，该脑干与孤立界（RNST）的Rostral核中的其他感觉输入集成在一起。了解接收此感觉输入的孤立核中神经元和神经胶质的初始发展将有助于更完整地了解中枢神经系统中的味觉信息如何为饮食选择提供信息，这是对维持生命重要的行为。确定在RNST中如何以及何时在分子水平上调节功能对于理解味觉系统的可塑性至关重要。因为动物必须在出生时进食，所以第一个必须起作用才能引导初始营养摄入。因此，重要的是要表征控制RNST正常发育的因素，以了解孕产妇饮食，饮酒和药物如何影响RNST的神经发育和突触发生。