Organization and Development of Functional Maps in Visual Cortex

 描述(由申请人提供)：确定视觉世界的特征如何在皮层回路的活动中表现，以及这些表征在发育过程中如何构建仍然是视觉神经科学的基本挑战，对于理解视觉感知的神经基础和皮质功能障碍是至关重要的。本方案中的实验继续我们对雪貂视皮层第2/3层柱状表征的功能组织和发展的分析。初步证据表明，第2/3层皮层回路对视觉刺激的表征有一个重要的新维度：由优先对漫射亮度增加(ON)或亮度降低(OFF)做出反应的神经元组成的柱状结构。通过使用柱状和细胞分辨率水平的功能性ON和OFF输入的体内成像技术的组合，我们将检验对漫射照明的ON和OFF反应在视皮层2/3层以模块化方式排列的假设，探索这种柱状结构的细胞学基础及其与定向偏好表征的关系，并探索经验独立和依赖机制对其发展的贡献。综上所述，这些实验将对调节视觉感知的皮质回路的功能组织和发展产生新的见解，为解决影响皮质回路功能的广泛神经和精神障碍提供基础知识。

 DESCRIPTION (provided by applicant): Establishing how features of the visual world are represented in the activity of cortical circuits, and how these representations are constructed during development remain fundamental challenges for visual neuroscience and are central to understanding the neural basis of visual perception and disorders of cortical function. The experiments in this proposal continue our analysis of the functional organization and development of columnar representations in layer 2/3 of ferret visual cortex. Preliminary evidence suggests an important new dimension to the representation of visual stimuli by layer 2/3 cortical circuits: a columnar architecture composed of neurons that respond preferentially to diffuse luminance increments (ON) or luminance decrements (OFF). By using a combination of techniques for in vivo imaging of functional ON and OFF inputs at the columnar and cellular level of resolution, we will test the hypothesis that ON and OFF responses to diffuse illumination are arranged in a modular fashion in layer 2/3 of visual cortex, explore the cellular basis for thi columnar architecture and its relation to the representation of orientation preference, and probe the contribution of experience independent and dependent mechanisms to its development. Taken together these experiments will yield novel insights into the functional organization and development of the cortical circuits that mediate visual perception, providing the foundational knowledge for addressing a broad range of neurological and psychiatric disorders that impact cortical circuit function.