Contextual modulation of orientation specificity in V1

V1 方向特异性的上下文调节

• 批准号: 6665280
• 负责人: David C Lyon
• 金额: $ 3.68万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-26 至 2004-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6665280
• 关键词: brain electrical activity; brain imaging /visualization /scanning; cats; confocal scanning microscopy; fluorescent dye /probe; microelectrodes; neural information processing; neuroanatomy; postdoctoral investigator; vision; visual cortex

DESCRIPTION (provided by applicant): The aim of this proposal is to identify the underlying intrinsic mechanisms of contextual modulation in primary visual cortex (V1). Though the basic drive of orientation selectivity of V1 neurons is known to derive from retinal relays of the lateral geniculate nucleus (LGN), modulation of this classical receptive field (CRF) is generated through lateral long-range connections within V1. This surround modulation can either suppress or enhance the response of a neuron to its CRF. Previous work from the Sur lab and others has shown that the direction of the modulation depends on the orientation of the surround and the contrast of the CRF. Furthermore, orientation preference maps are arranged so that transitions between preferred orientation domains can be smooth or fractured (where incongruent orientation domains are found adjacent to each other). There are indications that long-range inputs to these fracture sites come from an in-homogenous array of other orientation domains, whereas smooth, or iso-orientation domains are known to receive lateral connections primarily from like iso-orientation domains. The proposed experiments will use optical imaging to identify fracture sites for fluorescent tracer injections, and two-photon microscopy will be used to identify the resulting clusters of labeled cells in V1. By matching the sites of labeled cells with the orientation preference map we can define specifically which regions provide modulatory input. With this information we can discreetly stimulate these regions with optimal orientation displays and systematically measure the effects on the CRF.

描述（由申请人提供）：该提案的目的是确定主视觉皮层（V1）中情境调制的基本固有机制。尽管已知V1神经元的基本驱动方向选择性源自横向基因核（LGN）的视网膜继电器（LGN），但该经典接受场（CRF）的调节是通过V1中的横向长距离连接而产生的。这种环绕型调制可以抑制或增强神经元对其CRF的反应。 SUR实验室和其他人的先前工作表明，调制的方向取决于周围的方向以及CRF的对比度。此外，安排了方向偏好图，以便在首选方向域之间的过渡可以平滑或破裂（在发现不一致的方向域相互毗邻的情况下）。有迹象表明，这些断裂位点的远程输入来自其他方向域的内部源数阵列，而众所周知，光滑或同级方向域的光滑或同级方向域主要是从类似ISO方向域接收的横向连接。所提出的实验将使用光学成像来识别荧光示踪剂注射的断裂位点，并使用两光子显微镜来识别V1中标记的细胞的产生簇。通过将标记单元的位点与方向偏好图匹配，我们可以专门定义哪些区域提供调节输入。有了这些信息，我们可以通过最佳取向显示，并系统地测量对CRF的影响。