NEURONAL PATTERNS AND SYNAPSES IN CULTURED COCHLEA

拟议研究的总体目标是了解 神经元模式的发展和神经受体的分化 Corti的器官 该项目包括研究 培养物中的离体器官与完整动物的器官相比。 组织培养技术的使用具有特殊价值。 我们建议 项目后。 1. 胎儿发育的超微结构研究 培养耳蜗。 该项目与开发 胎鼠Corti器的神经支配模式。 三 将考虑的问题：a）在发展的顺序 胎儿Corti器中传入突触的形成，B） 毛细胞的分化和获得 突触，以及c）螺旋纤维的神经末梢的形态 在外毛细胞的神经支配延迟期， 这种现象在胎儿材料的培养中尤为明显。 2. 布朗克斯Waltzer突变体Corti器的光镜观察 老鼠在文化 该突变体提供了一种选择性的Corti器官， 由于内毛逐渐丧失而形成的外毛细胞群 细胞 该项目的目的是研究神经元模式， 内毛细胞的选择性丧失。 3. 的超微结构研究 在布朗克斯Waltzer突变小鼠的原位发育Corti器官， 观察传入性突触末梢及其 突触后位点与受体细胞变性的关系。 4. 研究 培养物中的囊泡神经末梢将在培养物中进行 在不同的出生后年龄，当这样的结局是已知的， 在完整的动物体内发育。 5. 突触形态的研究 在去传入神经的文化中的丝带。 特别令人感兴趣的将是一个后续行动 在去神经毛细胞中观察到的初步发现： 外毛细胞的突触带。 B -人数增加 免费丝带。 c -相互突触前复合体的形成 直接贴壁的毛细胞。

The overall objective of the proposed research is to comprehend the development of neuronal patterns and differentiation of neuroreceptors in the organ of Corti. The project comprises studies of the development of the isolated organ in culture as compared with that of the intact animal. Of special value is use of the tissue culture technique. We propose the following projects. 1. Ultrastructural study of the developing fetal cochlea in culture. The project is related to development of the innervation pattern in the organ of Corti of the fetal mouse. Three problems will be considered: a) the developmental sequence in the formation of afferent synapses in the fetal organ of Corti, b) the rlation between the differentiation of the hair cell and the acquisition of the synapse, and c) the morphology of the nerve endings of the spiral fibers during the period of innervation-delay of the outer hair cells, a phenomenon especially pronounced in cultures of fetal material. 2. Light-microscope study of the organ of Corti of the Bronx Waltzer mutant mouse in culture. The mutant provides an organ of Corti with a selective population of outer hair cells due to a progressive loss of inner hair cells. The project aims to study the neuronal patterns resulting from the selective loss of inner hair cells. 3. Ultrastructural study of the developing organ of Corti in situ of the Bronx Waltzer mutant mouse to observe the reaction of the afferent synaptic endings and their postsynaptic sites to the degeneration of the receptor cell. 4. Study of the vesiculated nerve endings in culture will be pursued in cultures explanted at different postnatal ages when such endings are known to develop in the intact animal. 5. Study of the patterns of synaptic ribbons in deafferented cultures. Of special interest will be a follow-up of preliminary findings observed in denervated hair cells: a - retaining of synaptic ribbons by the outer hair cells. b - increase in the number of free ribbons. c - formation of reciprocal presynaptic complexes between directly apposed hair cells.