Contextual modulation of orientation specificity in V1

V1 方向特异性的上下文调节

• 批准号: 6797339
• 负责人: David C Lyon
• 金额: $ 4.89万
• 依托单位: SALK INSTITUTE FOR BIOLOGICAL STUDIES
• 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 2005-09-25
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6797339
• 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)：本建议的目的是确定初级视觉皮质(V1)语境调制的潜在内在机制。虽然已知V1神经元定向选择性的基本驱动来自外侧膝状核(LGN)的视网膜中继，但这一经典感受野(CRF)的调制是通过V1内的外侧长距离联系产生的。这种环绕调制可以抑制或增强神经元对其CRF的反应。来自Sur实验室和其他人之前的工作已经表明，调制的方向取决于环绕的方向和CRF的对比度。此外，方向偏好图被安排为使得优选方向域之间的转变可以是平滑的或断裂的(其中发现不一致的方向域彼此相邻)。有迹象表明，到这些断裂点的远程输入来自不均匀的其他取向结构域阵列，而已知的光滑或等取向结构域主要从类似的等取向结构域接受侧向连接。拟议的实验将使用光学成像来识别荧光示踪剂注射的骨折部位，并将使用双光子显微镜来识别V1中产生的标记细胞簇。通过将标记细胞的位置与方向偏好图进行匹配，我们可以具体定义哪些区域提供调制输入。有了这些信息，我们就可以谨慎地用最佳取向显示来刺激这些区域，并系统地测量对CRF的影响。