DIFFERENTIATION OF OLFACTORY RECEPTOR NEURONS IN CULTURE

这项建议的总体目标是了解细胞 嗅觉感受器神经元存活的潜在和调节机制 差异化。众所周知，嗅球能发挥戏剧性的作用 嗅觉感受器神经元(ORN)存活的调控 差异化。我们假设与嗅球细胞的接触是 触发嗅觉最终功能分化的事件 感受器神经元。这一假设将通过准确地确定 特定的细胞和分子变化，以及细胞与细胞的相互作用 当嗅觉上皮(OE)细胞在没有或不存在的情况下生长时发生 在分离的细胞培养单层中，存在嗅球细胞。 首席研究员开发了新生大鼠的鼻腔培养 含有对气味有反应的电活动角的组织。 如果这些细胞共同诱导嗅觉标记蛋白(OMP)，就会发生OMP。 与嗅球星形胶质细胞共同培养。这些文化体系似乎 是研究嗅觉系统发育的极佳模型。 具体目标1：确定嗅觉感受器的分化特性 嗅球培养的嗅细胞在无嗅球条件下生长的神经元 细胞。我们将确定之前联系过的Orns是否 嗅球独特地含有OMP或具有不同的生存特性。 我们将确定之前接触过嗅球的Orns 唯一含有IMP或具有不同的生存特性。我们会 确定ORN存活率与OMP表达变化的关系有多密切。 我们将进一步定义ORN的电生理特性。特定目标 2：确定嗅觉感受器神经元的分化特性 在嗅球细胞存在的情况下生长。我们将确定OMP是否- 共培养中出现阳性神经元是因为神经发生或诱导 表达的方式。我们将确定变化是否也发生在1)ORN 电生理特性，2)或纤毛和3)存在 支持细胞。我们将确定OMP表达的调控是否 是嗅觉细胞特有的。一个特定的目标将是确定OMP 表达受细胞接触或可溶性因子的调节(S)。我们会 为未来对调节分子的研究定义一种检测系统。

The overall objective of this proposal is to understand the cellular mechanisms underlying and regulating olfactory receptor neuron survival and differentiation. The olfactory bulb (OF) is known to exert dramatic regulatory control over olfactory receptor neuron (ORN) survival and differentiation. We hypothesize that contact with olfactory bulb cells is the event which triggers final functional differentiation of olfactory receptor neurons. this hypothesis will be tested by pinpointing the specific cellular and molecular changes, and cell-cell interactions that occur when olfactory epithelial (OE) cells are grown in the absence or presence of olfactory bulb cells, in dissociated cell culture monolayers. The principal investigator has developed cultures of newborn rat nasal tissues that contain electrically active ORNs that respond to odorants. Induction of olfactory marker protein (OMP) occurs if these cells are co- cultured with olfactory bulb astrocytes. These culture systems appear to be an excellent model for studies of olfactory system development. Specific Aim 1: Define the differentiated properties of olfactory receptor neurons in olfactory cell cultures grown in the absence of olfactory bulb cells. We will determine if ORNs which had previously contacted the olfactory bulb uniquely contain OMP or have different survival properties. We will determine if ORNs which had previously contacted the olfactory bulb uniquely contain IMP or have different survival properties. We will determine how closely coupled ORN survival is to changes in OMP expression. We will further define ORN electrophysiological properties. Specific Aim 2: Define the differentiated properties of olfactory receptor neurons grown in the presence of olfactory bulb cells. We will determine if OMP- positive neurons appear in co-culture because of neurogenesis or induction of expression. We will determine if changes occur also in 1) ORN electrophysiological properties, 2) ORN cilia and 3) the presence of sustentacular cells. We will determine if regulation of OMP expression is specific to olfactory cells. A particular goal will be to determine if OMP expression is regulated by cell contact or a soluble factor(s). We will define an assay system for future investigation of regulatory molecules.