Department of Molecular and Cell Biology and Helen Wills Neurosciences Institute, University of California, Berkeley, Berkeley, California 94720, USA.
J Neurosci. 2010 Aug 18;30(33):11197-201. doi: 10.1523/JNEUROSCI.2302-10.2010.
Direction-selective ganglion cells (DSGCs) fire robustly for stimuli moving along one direction of motion and are strongly inhibited by stimuli moving in the opposite, or null, direction. In contrast to direction-selective neurons in primary visual cortex, a role for neural activity in the development of direction-selective retinal circuits has not been established. Direction-selective responses are detected at eye opening, before which spontaneous correlated activity known as retinal waves provide directional input to ganglion cells. Indeed, we observed a significant bias in wave propagation along the nasal over temporal direction. Using simultaneous calcium imaging and cell-attached recordings from three genetically labeled DSGC types in mice, we observed that all three DSGC types fire action potentials during retinal waves. However, we found that the direction of wave propagation did not influence DSGC spiking. These results indicate that the mechanisms guiding the formation of the asymmetric inhibition underlying direction selectivity in the retina are not dependent upon the directional properties of retinal waves.
方向选择性节细胞（DSGCs）对沿一个运动方向运动的刺激产生强烈的反应，并被沿相反方向或零方向运动的刺激强烈抑制。与初级视觉皮层中的方向选择性神经元不同，神经活动在方向选择性视网膜回路的发育中的作用尚未确定。在眼睛睁开时可以检测到方向选择性反应，在此之前，被称为视网膜波的自发相关活动为节细胞提供了方向输入。事实上，我们观察到波传播沿鼻侧到颞侧方向存在显著的偏差。通过在小鼠中使用同时的钙成像和细胞附着记录来自三种基因标记的 DSGC 类型，我们观察到所有三种 DSGC 类型在视网膜波期间都产生动作电位。然而，我们发现波传播的方向并不影响 DSGC 的放电。这些结果表明，指导视网膜中方向选择性下不对称抑制形成的机制不依赖于视网膜波的方向特性。
