Development of direction selectivity in retina

 描述（由申请人提供）：方向选择性神经节细胞对在优选方向上移动的图像响应强烈，而对在相反方向或零方向上移动的图像响应较弱。方向选择性神经节细胞对于驱动眼运动反射是至关重要的，当我们通过视觉场景移动时，它达特稳定视网膜上的图像，并且可以感知视觉场景中物体的运动。方向选择性神经节细胞的偏好方向沿着基本方向（上、下、左和右）聚集。在视网膜中产生方向选择性的主要模型是，特定类别的中间神经元在方向选择性神经节细胞的树突树的无效侧上形成抑制性突触。指导偏好方向出现的机制以及在发育过程中这些机制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的两个基本特征的发展的基础机制-优选方向的出现和产生空侧抑制的电路。特别是，我们将确定视觉体验是否在这些回路的形成中起着关键作用。

 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.