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Development of direction selectivity in the retina

视网膜方向选择性的发展

基本信息

批准号：
7634649
负责人：
Marla Feller
金额：
$ 35.08万
依托单位：
UNIVERSITY OF CALIFORNIA BERKELEY
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-07-01 至 2011-06-30
项目状态：
已结题

项目摘要

Direction-selective ganglion cells respond strongly to an image moving in the preferred direction and weakly to an image moving in the opposite, or null direction, and are critical for driving ocular-motor reflexes that stabilize images on the retina as we move through a visual scene. The preferred direction of direction-selective ganglion cells cluster along the cardinal directions (up, down, left and right) and the direction-selective ganglion cells sensitive to each cardinal direction are organized into mosaics such that at each point in space, each direction of motion is represented. The predominant model for the generation of direction selectivity in the retina is that a particular class of interneurons form inhibitory synapses on the null side of the dendritic tree of directionselective ganglion cells. The mechanisms that instruct the emergence of mosaics comprised of cells that receive an asymmetric distribution of inhibitory inputs during development are unknown. Our long-term goal is to determine the mechanisms that underlie the development of these two essential features of direction-selectivity - the circuits that underlie the null side inhibition and the existence of direction-selective ganglion cells mosaics. In particular, we will determine whether spontaneous retinal activity plays a critical role in the formation of these circuits. Here we propose to use a combination of state-of-the-art electrophysiological and imaging techniques to determine the age at which directional circuits are established.

方向选择性神经节细胞对在图像中移动的图像做出强烈反应首选方向，并且弱于沿相反方向或零方向移动的图像，并且对于驱动眼部运动反射至关重要，从而稳定视网膜上的图像在视觉场景中移动。方向选择性神经节细胞的首选方向沿着基本方向（上、下、左、右）进行聚类，并且方向选择性对每个基本方向敏感的神经节细胞被组织成马赛克，使得在空间中的每个点，表示每个运动方向。主导模型视网膜中方向选择性的产生是一类特定的中间神经元在方向选择性树突树的无效侧形成抑制性突触神经节细胞。指导马赛克出现的机制由在过程中接收不对称分布的抑制输入的细胞组成发展未知。我们的长期目标是确定发展的机制方向选择性的这两个基本特征 - 零点背后的电路侧抑制和方向选择性神经节细胞嵌合体的存在。在特别是，我们将确定自发性视网膜活动是否在这些电路的形成。在这里，我们建议使用最先进的组合电生理学和成像技术来确定定向年龄电路已建立。