Imaging and reversible inactivation of indirect inputs to area MT

描述(由申请人提供)：主要目标是研究视觉皮质运动计算的功能组织。灵长类区域MT与运动知觉和眼动的产生密切相关，然而，关于其多个汇聚输入来源中的每一个的功能作用，人们知之甚少。这些信息对于我们理解神经回路如何构成感知和行为是至关重要的，并可能对视觉系统的紊乱有重要的影响。拟议的研究将集中在灵长类区域MT，并将使用可逆失活和双光子显微镜评估来自V2的输入的具体贡献。我们将首先对从V2投射到MT的细胞进行逆行标记，并使用双光子显微镜对其活动进行成像。MT投射细胞的视觉反应特性将被表征，并与附近的其他细胞和V2中跨功能隔间的其他细胞进行比较。特别感兴趣的是被认为是首先在MT内计算的响应属性，以及那些被认为通过V2而不是其他已知输入路径传递到MT的响应属性。下一步，我们将用冷冻甲醇通过植入月状沟的线圈可逆地灭活V2。然后，可以在清醒的猕猴中测量MT反应特性和行为表现，无论有没有活动的V2。将特别强调研究V2在向MT提供运动方向和双眼视差信息方面的作用。这项研究将使我们更好地理解我们的大脑如何处理视觉场景，并调节我们感知移动物体的能力。这些信息不仅将阐明健康大脑的复杂过程，还将使我们对受衰老和精神疾病影响的大脑区域有重要的洞察。特别是，一些精神障碍，如精神分裂症和帕金森氏症，在视觉运动知觉方面有选择性缺陷，更好地理解这些疾病涉及的神经机制可能有助于缓解这些症状

DESCRIPTION (provided by applicant): The primary goal is to investigate the functional organization of motion computations in visual cortex. Primate area MT is intimately linked to the perception of motion and the generation of eye movements, yet little is known regarding the functional role of each of its multiple sources of convergent input. This information is critical to our understanding of how neural circuits underlie perception and behavior, and may have important implications for disorders of the visual system. The proposed studies will focus on primate area MT and will assess the specific contributions of inputs from V2 using reversible inactivation and two photon microscopy. We will first retrogradely label cells that project from V2 to MT and image their activity using two-photon microscopy. The visual response properties of MT-projecting cells will be characterized and compared to other cells nearby and across functional compartments within V2. Of particular interest will be response properties thought to be computed first within MT as well as those thought to be relayed to MT through V2 rather than other known input pathways. Next, we will reversibly inactivate V2 with chilled methanol perfused through coils implanted into the lunate sulcus. MT response properties and behavioral performance can then be measured in the awake, behaving macaque monkey with and without an active V2. Special emphasis will be given to investigating the role of V2 in providing MT with direction of motion and binocular disparity information. This research will lead to a better understanding of how our brain processes a visual scene and mediates our ability to perceive moving objects. Not only will this information elucidate the complex processes of the healthy brain, but it will also give us important insight into the brain regions affected by aging and mental disease. In particular, several mental disorders such as schizophrenia and Parkinson's disease have selective deficits in visual motion perception, and a better understanding of the neural mechanisms involved in these conditions may inform efforts to alleviate these symptoms