Organization of Auditory Thalamocortical Pathways

这些实验的长期目标是确定初级听觉皮质(AI)的功能特性与内侧膝状体(MGV)腹侧分裂产生的丘脑皮质斑块投射之间的相关性。与其他感觉系统不同，辅助人工智能功能图的丘脑皮质通路没有很好的定义。几个物种的人工智能中存在功能特性的零星或不连续的组织。从MGB腹侧部向AI的丘脑皮质也存在斑片状或不连续的投射模式。此外，MGV内投射到AI的两个主要区域(外侧部和卵形部)已经通过细胞结构、功能特性和免疫细胞化学进行了区分，有证据表明存在从MGV到AI的多条平行通路。这些多条通路可能编码不同的功能特性。在特定目标1中，我们将确定从MGV到AI的斑块TC投射与AI中的功能反应簇之间的关系。在特定的目标2中，我们将表征来自LV和OV的TC到AI的投影，以确定它们是否以独特的方式投射到AI并产生新的功能属性类别。BDA注射将专门针对IV和OV。在具体目标3中，我们将描述和比较MGV中单个、完全重建的中继细胞的TC投影模式。拟议的研究将定义人工智能中存在的功能特性的解剖学基础，并表征从MGV到AI的多个并行电路。

The long term goal of these experiments is to define the correlation between functional properties in primary auditory cortex (AI) and the patchy thalamocortical projections that arise from the ventral division of the medial geniculate body (MGV). Unlike other sensory systems, the thalamocortical pathways that subserve functional maps AI are not well defined. A patchy or discontinuous organization of functional properties exists in AI of several species. There also exists a patchy or discontinuous thalamocortical projection pattern from the ventral division of the MGB to AI. Further, two major areas (pars lateralis and pars ovoidea) within the MGV that project to AI have been differentiated by cellular architecture, functional properties and immunocytochemistry, and there is evidence to suggest the existence of multiple parallel pathways from MGV to AI. These multiple pathways may encode different functional properties. In specific aim 1 we will determine the relationship between patchy TC projections arising from MGV to AI and functional response clusters in AI. In specific aim 2 we will characterize TC projections to AI arising from the LV and OV to determine if they project in a unique way to AI and give rise to novel classes of functional properties. BDA injections will target the IV and OV specifically. In specific aim 3 we will characterize and compare the TC projection patterns single, fully reconstructed relay cells in the MGV. The proposed studies will define the anatomical substrates for functional properties that exist in AI and characterize multiple parallel circuits from MGV to AI.