DIFFERENTIATION AND CALCIFICATION OF OTOLITHS

在这个实验室中应用了以下技术的初步结果 拟议的调查表明：1)原始耳锥 起源于未成熟的耳石膜的分段，以及2) 钙颗粒(直径20-150 nm)首先附着在 原始耳锥的外表面，随后 结合到有机基质中。这项拟议的研究打算扩大 这些发现是为了全面调查这些 在时间和空间(年龄/地点)上的过程。 这项研究旨在描述最终导致形态变化的特征 随着鸡胚耳石的分化和成熟，通过：1) 未成熟耳石分割过程的细节分析 膜，2)分析有机之间存在的关系 母质和矿物成分，即起源、迁移和 含钙颗粒的分布；3)分析含钙颗粒 前庭黄斑上皮细胞的分化和成熟 迷宫。胚胎成熟度与成熟度之间的形态相关性 耳石和黄斑上皮，特别强调突触的形成 在每个阶段，都会进行。12个年龄在3-21岁之间的人 将审查孵化天数(阶段15-46)。 将采用光镜和电子显微镜组织化学方法并连续加厚 将获得黄斑的薄层切片，以确定 可能导致不同发展梯度的区域变化 对于每一个斑点。 耳石为感官和生理提供了不可或缺的线索。 对环境的定位。尽管前庭异常 神经和核团导致姿势失衡和共济失调，即耳石 末端器官为引力探测提供主要输入。如果没有 耳石脊椎动物很难保持身体平衡。 尽管如此，人们对它们的发展知之甚少。我们必须充分 先了解耳石的正常发育，然后才能开始 了解遗传缺陷和致畸剂在 胚胎耳朵。

Preliminary results in this laboratory applying the techniques outlined for the proposed investigation have shown that: 1) primitive otoconia originate from segmentation of an immature otolithic membrane, and 2) that calcium granules (20-150 nm in diameter) first become attached to the external surface of the primitive otoconia and are subsequently incorporated into the organic matrix. The proposed study intends to expand these findings in order to fully investigate the progression of these processes in time and space (age/location). The study intends to characterize the morphological changes that culminate with the differentiation and maturation of chick embryo otoliths by: 1) analyzing the details of the segmentation process of the immature otolithic membrane, 2) analyzing the relationship that exists between the organic matrix and the mineral components, i. e., origin, migration and distribution of the calcium containing granules, and 3) analyzing the differentiation and maturation of the macular epithelia in the vestibular labyrinth. A morphological correlation between the maturation of the otoliths and the macular epithelia, with special emphasis on synaptogenesis at each stage, will be carried out. Twelve different ages between 3-21 days of incubation (stages 15-46) will be examined. Light and electron microscopy histochemistry will be used and serial thick and thin sections of the maculae will be obtained in order to determine the regional changes that probably result in different developmental gradients for each macula. The otoliths provide indispensable cues for sensory perception and physical orientation to the environment. Although abnormality of the vestibular nerve and nuclei contribute to postural imbalance and ataxia, the otolithic end organs provide the primary input for gravitational detection. Without the otoliths vertebrates have great difficulty keeping body balance. Nonetheless, little is known about their development. We must fully understand the normal development of the otoliths before we can begin to understand the changes that genetic deficits and teratogens produce in the embryonic ear.