Synaptic connectivity in mouse accessory olfactory bulb

描述（由申请人提供）：副嗅球（AOB）是犁鼻系统中化学感受信息的第一个中继，但很少有研究涉及AOB中细胞的细胞生理学和突触连接。AOB中的主要神经元与主嗅球（MOB）中的细胞不同，将初级树突发送到多于一个肾小球，并且在犁鼻器（VNO）中表达单个犁鼻受体（VR）的外周感觉神经元投射到多个肾小球。也有一个隔离的投射从感觉神经元在VNO到AOB的前面和后面的方面，这种隔离也可能导致在这些地区的活动模式的差异。本申请的总体目标是研究AOB中主要神经元的生理特性。我们将涉及的细胞，特别是肾小球连接的解剖参数的生理特性，以及它们在AOB的前后轴的分布。在具体目标1中，我们将确定二尖瓣细胞是否仅与接受来自相同受体的输入的肾小球连接，或者同一二尖瓣细胞是否与混合受体群体保持连接。我们将使用两种转基因小鼠，V1 r和V2 r-GFP小鼠。从连接到GFP标记的肾小球的二尖瓣细胞记录并在细胞内记录溶液中包括荧光染料将允许鉴定细胞的肾小球连接。我们将比较GFP标记的肾小球与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中树突状细胞抑制的药理学和生理学特性。因为表达V1 r和V2 r的VNO神经元分别投射到前部和后部AOB，所以使用这些转基因小鼠将允许我们比较AOB的这些细分。预计这些研究将对我们理解辅助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.