Functional Organization of Primary Auditory Cortex

拟议实验的长期目标是确定基本的处理原理和 构成皮层感受场转换和复杂声音表示的策略。 我们将比较成年猫的两个主要听域Al和AAF的组织与特定的 对功能域和层次化组织的引用。一个主要前提是Al和AAF在很大程度上 独立的丘脑和大脑皮层输入，并有可能构成任务的特定功能差异- 特定的处理流。输入在源位置和功能属性上有何不同；有什么不同 丘脑输入对感受野(RF)多样性的产生有贡献； 大脑皮层输入水平的特征在输出层中转换？ 功能性质的异质空间分布之间的相互关系及其联系 这些主要区域的模式将在联合电生理学和神经解剖学实验中进行研究。 通过将功能属性和大脑皮层连通性联系起来，这些特征背后的全球原则 对于简单和复杂的声音，可以评估大脑皮层表示和转换的能力。 。第一个目标是定义Al和AAF的特定于层的功能组织，分为简单和复杂 听起来。我们认为，Illb/IV层中的单个神经元在射频属性上将显示出系统性的差异 其他层中的单元格。RFS将使用传统刺激以及反向相关方法来获得 这就产生了双耳的光谱-时间接受场。我们还将比较特定于椎板的变化 麻醉猫的Al和AAF和A！唤醒的松鼠猴子的地址 有意识的动物的比较问题和射频组织。 第二个目标是通过同时比较丘脑源和皮质靶点的RFs 猫内侧膝状体和AI/AAF功能连接神经元对的记录这是假设的 丘脑输入特性与其皮质目标的某些射频特性相似，但该结构 许多大脑皮层RFS在很大程度上是由皮质贡献决定的。 最后，我们将把丘脑和皮质内的联系与Al和AAF的功能亚区联系起来。多么 丘脑和皮质的斑片状投射与发现的斑片状皮质组织有关 光谱、时间和双耳特性是主要问题。逆行注射示踪剂的标记 将根据功能图对CAT AI/AAF中生理定义的功能区进行评估。 这些研究将建立初级皮层信号处理的功能和结构框架 菲尔兹。对这些原理的洞察对于理解听觉皮质中的信息流至关重要。 正常听觉处理和知觉学习的回路，以及它们对听觉障碍的贡献。

The long-term goal of the proposed experiments is to identify the fundamental processing principles and strategies that underlie the cortical receptive field transformations and representations of complex sounds. We will contrast the organization of two primary auditory fields, Al and AAF, in adult cat with specific reference to functional domains and laminar organization. A main premise is that Al and AAF receive largely independent thalamic and cortical inputs and have specific functional differences that may constitute task- specific processing streams. How do the inputs differ in source location and functional properties; what do the thalamic inputs contribute to the generation of receptive field (RF) diversity; and how are the functional characteristics at the cortical input level transformed in the output layers? The interrelations between heterogeneous spatial distributions of functional properties and the connection patterns of these primary fields will be studied in joint electrophysiological and neuroanatomical experiments. By relating the functional properties and cortical connectivity, global principles underlying the characteristics of cortical representations and transformations can be assessed for simple and complex sounds. . The first aim is to define layer-specific functional organizations of Al and AAF for simple and complex sounds. We think that single neurons in layers Illb/IV will show systematic differences in RF attributes from cells in other layers. RFs will be obtained with traditional stimuli as well as with a reverse-correlation method that creates binaural spectro-temporal receptive fields. We will also compare the lamina-specific changes in RF properties in Al and AAF of the anesthetized cat and in A! of the awake squirrel monkey to address comparative questions and RF organization in conscious animals. The second aim is to compare directly the RFs of thalamic sources and cortical targets by simultaneous recording of functionally connected neuron pairs in cat medial geniculate body and AI/AAF. It is hypothesized that thalamic input properties approximate some RF properties of their cortical targets but that construction of many cortical RFs is substantially shaped by corticocortical contributions. Finally, we will relate thalamic and intracortical connections to functional sub-regions of Al and AAF. How patchy thalamic and corticocortical projections are related to the patchy cortical organizations found for spectral, temporal and binaural properties is the main question. Labeling from retrograde tracers injected into physiologically defined functional zones in cat AI/AAF will be assessed relative to functional maps. These studies will establish a functional and structural framework of signal processing in primary cortical fields. Insight into these principles is crucial for understanding the flow of information in auditory cortex, the circuits for normal auditory processing and perceptual learning, and their contributions to auditory disorders.