Development of direction selectivity in retina

 描述(申请人提供)：方向选择性神经节细胞对沿首选方向移动的图像反应强烈，而对沿相反方向或零方向移动的图像反应弱。当我们在视觉场景中移动时，方向选择性神经节细胞对于驱动眼球运动反射以稳定视网膜上的图像以及感知视觉场景中物体的运动至关重要。方向选择性神经节细胞的优先方向沿基本方向(上、下、左、右)聚集。视网膜产生方向选择性的主要模式是，一类特定的中间神经元在方向选择性神经节细胞的树状突触树的零侧形成抑制性突触。指导优先方向出现的机制以及这些机制在发育过程中的基础电路尚不清楚。在这里，我们建议使用最先进的电生理学、双光子成像和光遗传学技术的组合来确定方向选择性两个基本特征发展的机制--优先方向的出现和产生无效侧抑制的电路。特别是，我们将确定视觉体验是否在这些回路的形成中发挥关键作用。

 DESCRIPTION (provided by applicant): 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. Direction-selective ganglion cells are critical for driving ocular-motor reflexes tat stabilize images on the retina as we move through a visual scene as well as for sensing the movement of objects within the visual scene. The preferred directions of direction- selective ganglion cells cluster along the cardinal directions (up, down, left and right). The predominant model for the generation of direction selectivity in the retina is that a particular class of interneurons forms inhibitory synapses on the null side of the dendritic tree of direction-selectiv ganglion cells. The mechanisms that instruct the emergence of preferred directions and the circuits that underlie these mechanisms during development are unknown. Here we propose to use a combination of state-of-the-art electrophysiological, two- photon imaging and optogenetic techniques to determine the mechanisms that underlie the development of two essential features of direction-selectivity - the emergence of preferred directions, and the circuits that create null side inhibition. In particular, we will determine if visual experience plays a criticalrole in the formation of these circuits.