Synaptic connectivity in mouse accessory olfactory bulb

描述(申请人提供)：副嗅球(AOB)是犁鼻系统中第一个传递化学感觉信息的中继器，但很少有研究涉及AOB中细胞生理学和细胞的突触连接。与主嗅球(MOB)中的细胞不同，AOB中的主神经元将初级树突发送到多个肾小球，而表达单个犁鼻器受体(VR)的外周感觉神经元则投射到多个肾小球。迷走神经核内感觉神经元的投射也被分离到AOB的前部和后部，这种分离也可能导致这些区域不同的活动模式。这一应用的总体目的是研究AOB中主要神经元的生理特性。我们将把生理特征与细胞的解剖参数联系起来，特别是肾小球的连通性，以及它们在AOB前后轴上的分布。在特定的目标1中，我们将确定二尖瓣细胞是否只与接受相同受体输入的肾小球相连，或者是否相同的二尖瓣细胞与混合受体群体保持联系。我们将使用两种转基因小鼠，V1r和V2r-GFP小鼠。从连接到绿色荧光蛋白标记的肾小球的二尖瓣细胞进行记录，并在细胞内记录溶液中包括荧光染料，将允许识别细胞的肾小球连接(S)。我们将比较GFP标记的肾小球和细胞内染料标记的肾小球的数量。在具体目标2中，我们将研究二尖瓣细胞树突状细胞抑制的药理学和生理学特性。由于表达V1r和V2r的VNO神经元分别投射到AOB的前部和后部，使用这些转基因小鼠将使我们能够比较AOB的这些细分。预计这些研究将对我们理解副嗅觉系统对信息素信息和其他嗅觉信息的感觉编码产生影响。

DESCRIPTION (provided by applicant): The accessory olfactory bulb (AOB) is the first relay of chemosensory information in the vomeronasal system, yet very few studies have addressed cell physiology and synaptic connectivity of cells in the AOB. Principal neurons in the AOB, unlike cells in the main olfactory bulb (MOB), send primary dendrites to more than one glomerulus, and peripheral sensory neurons expressing a single vomeronasal receptor (VR) in the vomeronasal organ (VNO) project to multiple glomeruli. There is also a segregation of projections from sensory neurons in the VNO into the anterior and posterior aspects of the AOB, and this segregation may also result in differential patterns of activity in these regions. The overall aim of this application is to study the physiological properties of principal neurons in the AOB. We will relate physiological characteristics to anatomical parameters of the cells, particularly glomerular connectivity, and their distribution in the anterior-posterior axis of the AOB. In Specific Aim 1, we will determine if mitral cells are connected only to glomeruli that receive inputs from the same receptor, or if the same mitral cell maintains connection with a mixed population of receptors. We will use two lines of transgenic mice, the V1r and V2r-GFP mice. Recording from mitral cells connected to GFP-labeled glomeruli and including a fluorescent dye in the intracellular recording solution will allow identification of the cell's glomerular connection(s). We will compare the number of GFP-labeled glomeruli with those labeled by the intracellular dye. In Specific Aim 2, we will study the pharmacological and physiological properties of dendrodendritic inhibition in mitral cells. Because VNO neurons expressing the V1r and V2r project to the anterior and posterior AOB respectively, the use of these transgenic mice will allow us to compare these subdivisions of the AOB. It is anticipated that these studies will have an impact on our understanding of the sensory coding of pheromonal information and other olfactory information by the accessory olfactory system.