DIFFERENTIATION OF OLFACTORY RECEPTOR NEURONS IN CULTURE

本提案的总体目标是了解蜂窝 嗅觉受体神经元存活的基础和调节机制， 分化 嗅球（OF）是众所周知的发挥戏剧性的 嗅觉受体神经元（ORN）存活的调节控制， 分化 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 受体神经元 这一假设将通过精确定位 特定的细胞和分子变化，以及细胞间相互作用， 当嗅上皮（OE）细胞在缺乏或缺乏的情况下生长时， 解离细胞培养单层中存在嗅球细胞。 主要研究者开发了新生大鼠鼻粘膜的培养物， 含有对气味有反应的电活性ORN的组织。 嗅觉标记蛋白（OMP）的诱导发生，如果这些细胞是共同的， 与嗅球星形胶质细胞一起培养。 这些文化体系似乎 是研究嗅觉系统发育的极好模型。 具体目标1：明确嗅觉感受器的分化特性 嗅球缺失条件下培养的嗅细胞中的神经元 细胞 我们将确定以前联系过 嗅球中唯一含有OMP或具有不同的生存特性。 我们将确定之前接触过嗅球的ORN 唯一含有IMP或具有不同的生存特性。 我们将 确定ORN存活与OMP表达变化的密切关系。 我们将进一步定义ORN的电生理特性。 具体目标 2：定义嗅觉受体神经元的分化特性 在嗅球细胞的存在下生长。 我们将确定OMP是否- 在共培养中由于神经发生或诱导而出现阳性神经元 的表达。 我们将确定1）ORN是否也发生变化 电生理特性，2）ORN纤毛和3）的存在 支持细胞 我们将确定OMP表达的调节是否是 特异于嗅觉细胞。 一个特定的目标将是确定OMP是否 表达受细胞接触或可溶性因子调节。 我们将 为将来的调节分子研究定义一个测定系统。

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.