Development of direction selectivity in the retina

方向选择性神经节细胞强烈响应图像移动在 优选方向，并且弱于在相反方向或零方向上移动的图像，以及 是驱动眼球运动反射的关键，当我们在视网膜上时， 在视觉场景中移动。方向选择性神经节细胞的偏好方向 集群沿着基本方向（上，下，左，右）和方向选择 对每个基本方向敏感的神经节细胞被组织成马赛克， 在空间中的每个点处，表示每个运动方向。主导模式 对于视网膜中方向选择性的产生， 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。 神经节细胞指示马赛克出现的机制 由接受非对称分布的抑制性输入的细胞组成， 发展未知。 我们的长期目标是确定发展的基础机制， 方向选择性的这两个基本特征--零点的电路 侧抑制和方向选择性神经节细胞镶嵌的存在。在 特别是，我们将确定自发性视网膜活动是否起着关键作用， 这些电路的形成。在这里，我们建议使用最先进的 电生理和成像技术，以确定在哪个年龄的方向 电路已经建立。

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.