Functional Organization of Visual Area MT

描述（由申请人提供）：大脑皮层由许多相对离散的区域组成，这些区域专门负责各种功能。在视觉系统中，这些区域之间的联系是有序的和分层的，在更高的层次上出现了相对更抽象的视觉世界表征。此外，不同的视觉属性，如运动和颜色，大致上是在单独的并行“流”中处理的。然而，视觉系统还具有不同处理流之间丰富的互连集的特征，因此任何给定的区域都将接收来自许多其他区域的输入。在产生一组给定神经元的特定响应特性时，各种不同的输入的作用是什么？我们建议使用中颞叶视觉区（MT或V5）作为模型系统来解决这个问题。由于在MT神经元中已经确定了许多更高层次的视觉运动计算，并且由于信息流的不同路线相当熟悉，我们可以开始剖析各种输入在产生更复杂的接受野属性中所起的作用。本研究将重点关注脑皮层和皮层下通路之间的解剖学和功能关系。结合新的解剖学技术（多突触、逆行病毒示踪剂）、功能技术（单单元记录、可逆失活、2-脱氧葡萄糖）和行为（眼动），将阐明所谓的“间接通路”在塑造脑皮层神经元反应特性中的作用。这些实验的结果将使我们更好地理解产生MT神经元接受野特性的皮质电路，以及它们在感知和视觉引导行为中所起的作用。最终，这些研究将使我们了解精神生活的生物学基础，这对精神障碍的治疗和治愈至关重要。

DESCRIPTION (provided by applicant): The cerebral cortex consists of numerous, relatively discrete, areas that are specialized for various functions. In the visual system, the connections between these areas are orderly and hierarchical, with relatively more abstract representations of the visual world emerging at higher levels of the hierarchy. In addition, different visual attributes, such as motion and color, are, to a first approximation, processed in separate, parallel "streams." However, the visual system is also characterized by rich sets of interconnections between different processing streams, so that any given area will receive inputs from many other areas. What is the role of the various different inputs in generating the particular response properties of a given set of neurons? We propose to use the middle temporal visual area (MT or V5) as a model system with which to address this question. Because a number of higher-level visual motion computations have been identified in MT neurons, and because the different routes of information flow are reasonably well known, we can begin to dissect the role played by the various inputs in generating more complex receptive field properties. This proposal will focus on the anatomical and functional relationships between cortical and subcortical pathways to MT. A combination of novel anatomical techniques (multi-synaptic, retrograde viral tracers), functional techniques (single unit recording, reversible inactivation, 2-deoxyglucose) and behavior (eye movements) will be used to elucidate the role of the so-called "indirect pathways" in shaping the response properties of MT neurons. The result of these experiments will be a better understanding of the cortical circuitry that gives rise to the receptive field properties of MT neurons and of the role that they play in perception and visually guided behavior. Ultimately, these studies will inform our understanding of the biological basis of mental life, which is critical for the treatment and cure of mental disorders.