The Role of LGN Directional Selectivity in Visual Cortical Processing

LGN 方向选择性在视觉皮层处理中的作用

• 批准号: 10248300
• 负责人: HARVEY A SWADLOW
• 金额: $ 19.52万
• 依托单位: UNIVERSITY OF CONNECTICUT STORRS
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10248300
• 关键词: Address; Axon; Behavior Disorders; Cell Nucleus; Cells; Clinical; Clinical Research; Complex; Disease; Felis catus; Future; Inherited; Interneurons; Lateral Geniculate Body; Mental Health; Methods; Midbrain structure; Motion; Motion Perception; Mus; Neurons; Oryctolagus cuniculus; Photic Stimulation; Population; Primates; Property; Retina; Retinal Ganglion Cells; Rodent; Role; Somatosensory Cortex; Source; Stream; Synapses; Thalamic structure; Training; V1 neuron; Vision Disorders; Visual Cortex; Visual system structure; Work; area striata; awake; base; density; experimental study; extracellular; orientation selectivity; preference; presynaptic; receptive field; response; retinal axon; retinotopic

PROJECT SUMMARY The lateral geniculate nucleus (LGN) of rabbits and rodents contains a population of neurons that show strong directional selectivity (DS) to visual stimulation. Although these LGN DS neurons are known to project to the primary visual cortex (V1), their synaptic targets, and their role in the synthesis of V1 receptive fields are unknown. Whereas in cats and primates, LGN neurons display little or no orientation and directional selectivity and these properties are thought to be largely synthesized within V1, in rabbits and rodents these properties could potentially be inherited, in part, from the LGN DS neurons. The proposed experiments will address this question, aiming to understand how LGN DS neurons contribute to the synthesis of the diverse receptive field seen in V1 neurons. This will be accomplished using two sets of complementary methods, in fully awake rabbits. First (Aim 1), we will determine which layers of V1 receive a strong input from LGN DS neurons. We will do this using single-axon spike-triggered current source-density analysis, a method that provides a view of the laminar profile of the presynaptic (axonal) and monosynaptic local field potentials and currents generated by the spikes of single thalamocortical neurons within the topographically aligned region of recipient cortex. Next (Aim 2), we will record the spike trains of both LGN DS neurons, and retinotopically aligned cortical neurons of different receptive field classes. We will determine which cortical neurons within the synaptic recipient zone of the LGN DS neuron receives synaptic input (using methods of extracellular cross-correlation), and how the directional preferences of the LGN DS neurons relate to the preferences of their synaptic targets. Direction and orientation selectivity are among the most salient response properties of visual cortical neurons and this project is aimed at understanding how these properties emerge.

项目摘要 兔子和啮齿动物的侧向基因核（LGN）包含一群神经元的种群 表现出强烈的定向选择性（DS）对视觉刺激。尽管这些LGN DS神经元是 已知要投射到主要视觉皮层（V1），其突触靶标及其在合成中的作用 V1接收场的未知。而在猫和灵长类动物中，LGN神经元几乎没有或没有显示 方向和定向选择性以及这些特性在很大程度上被认为是在很大程度上合成的 v1，在兔子和啮齿动物中，这些特性可能部分从LGN DS继承 神经元。拟议的实验将解决这个问题，旨在了解LGN DS 神经元有助于V1神经元中看到的多种接受场的合成。这将是 完全清醒的兔子使用两组互补方法完成。首先（AIM 1），我们将 确定哪个V1层接收到LGN DS神经元的强烈输入。我们将使用 单轴尖峰触发的电流密度分析，一种提供了视图的方法 突触前（轴突）和单突触的局部田间电势和电流的层状轮廓 由单个丘脑皮质神经元的尖峰产生 收件人皮质。接下来（AIM 2），我们将记录两个LGN DS神经元的尖峰火车，并记录 不同接受场类别的视网膜对齐的皮质神经元。我们将确定哪个 LGN DS神经元的突触受体区域内的皮质神经元接收突触输入 （使用细胞外交叉相关方法），以及LGN DS的定向偏好 神经元与其突触靶的偏好有关。方向和方向选择性是 视觉皮质神经元最显着的响应特性之一，该项目针对 了解这些特性如何出现。