Molecular Analysis of Olfactory Sensory Imputs

描述(摘自申请者摘要)：嗅觉系统类似于 其他感觉系统将感觉刺激转化为不同的 感知。然而，它提供了使用分子的独特机会 阐明信息是如何从感觉刺激中提取的方法 然后在大脑中组织起来，产生不同的感知。这个机会 源于这一发现，气味检测大约通过1000 嗅觉传感器表达的不同气味受体(OR) 鼻嗅觉上皮(OE)内的神经元。来自OE的信号是 通过嗅觉公牛(OB)，然后嗅觉皮质(OC)传递到 其他脑区。每个OSN表达一个OR基因。在OE，4个区域快递 不同的OR集合。表达相同OR的OSN分散在一个区域内。 然而，它们的轴突会聚在几个特定的OB肾小球中，产生 OR输入的精确映射。汉字纹样的功能意义 还不了解OE和OB，也不知道OR输入是如何组织的 超越了OB。另一个重要的问题是，关于多样化的信息如何 气味结构被组织起来以产生不同的气味感知。最近 我们发现，不同的气味由不同的组合识别 ORS。单一气味被高度相关和发散的ORs识别， 而一些在气味物质中区别的OR值只有一个官能团不同 而其他人则不是。 在这项建议中描述的研究中，我们将进一步探讨如何 嗅觉信息由OR家族从气味结构中获得。我们 还将研究这些信息在嗅觉系统中是如何组织的。我们 将首先使用OSNs的钙成像和单细胞PCR相结合的方法来 识别具有相同碳链的n-脂肪族气味的OR，但 各种不同的官能团。然后，我们将每个OR表示为 并进一步鉴定它们的气味特性。基于我们的 之前的发现，我们希望确定高度相关和不同的OR， 其中一些可以区分不同官能团和 其他人则不会。使用原位杂交，我们将询问是否 OR的功能或其结构与 OE中的区域或OB中肾小球的特殊排列。 最后，我们将使用基因打靶技术来产生共表达a基因的小鼠。 具有单一OR基因的跨神经元示踪剂，以确定如何输入 来自单个OR的输入是否组织在OC中，以及来自OR的输入是否 具有不同官能团的气味针对特定的皮质 地区。

DESCRIPTION (From the Applicant's Abstract): The olfactory system resembles other sensory systems in its ability to translate sensory stimuli into distinct perceptions. However, it offers unique opportunities to use molecular approaches to elucidate how information is extracted from sensory stimuli and then organized in the brain to yield different perceptions. This opportunity stems from the finding that odorant detection is mediated by approximately 1000 different odorant receptors (ORs), which are expressed by olfactory sensor neurons (OSNs) in the nasal olfactory epithelium (OE). From the OE, signals are relayed through the olfactory bull (OB) and then the olfactory cortex (OC) to other brain areas. Each OSN expresses one OR gene. In the OE, 4 zones express different sets of ORs. OSNs expressing the same OR are scattered in one zone. However, their axons converge in a few specific OB glomeruli, generating a precise map of OR inputs. The functional significance of the patterning of the OE and OB is not yet understood, nor is it known how OR inputs are organized beyond the OB. Another important question is how information about diverse odorant structures is organized to yield different odor perceptions. Recently we found that different odorants are recognized by different combinations of ORs. A single odorant was recognized by both highly related and divergent ORs, and some ORs distinguished among odorants that differed by a single functional group whereas others did not. In the studies described in this proposal, we will further explore how olfactory information is obtained from odorant structures by the OR family. We will also examine how that information is organized in the olfactory system. We will first use a combination of calcium imaging of OSNs and single cell PCR to identify ORs for n-aliphatic odorants that have the same carbon chains, but a variety of different functional groups. We will then express each of the ORs in a cell line and further characterize their odorant specificities. Based on our previous findings, we expect to identify both highly related and divergent ORs, some of which will distinguish odorants that differ in functional group and others that will not. Using in situ hybridization, we will then ask whether there are correlations between the function of an OR, or its structure, and either zones in the OE or the particular arrangement of glomeruli in the OB. Finally, we will use gene targeting to generate mice that coexpress a transneuronal tracer with a single OR gene in order to determine how inputs from individual ORs are organized in the OC and whether inputs from ORs for odorants with different functional groups are targeted to specific cortical regions.