Committee on Neurobiology Graduate Program, The University of Chicago, Chicago, United States.
Department of Neurobiology, The University of Chicago, Chicago, United States.
Elife. 2021 Jun 7;10:e68181. doi: 10.7554/eLife.68181.
Spatially distributed excitation and inhibition collectively shape a visual neuron's receptive field (RF) properties. In the direction-selective circuit of the mammalian retina, the role of strong null-direction inhibition of On-Off direction-selective ganglion cells (On-Off DSGCs) on their direction selectivity is well-studied. However, how excitatory inputs influence the On-Off DSGC's visual response is underexplored. Here, we report that On-Off DSGCs have a spatially displaced glutamatergic receptive field along their horizontal preferred-null motion axes. This displaced receptive field contributes to DSGC null-direction spiking during interrupted motion trajectories. Theoretical analyses indicate that population responses during interrupted motion may help populations of On-Off DSGCs signal the spatial location of moving objects in complex, naturalistic visual environments. Our study highlights that the direction-selective circuit exploits separate sets of mechanisms under different stimulus conditions, and these mechanisms may help encode multiple visual features.
空间分布的兴奋和抑制共同塑造了视觉神经元的感受野(RF)特性。在哺乳动物视网膜的方向选择性电路中,对 On-Off 方向选择性神经节细胞(On-Off DSGCs)的强无方向抑制在其方向选择性中的作用已经得到了很好的研究。然而,兴奋性输入如何影响 On-Off DSGC 的视觉反应还没有得到充分的探索。在这里,我们报告说,On-Off DSGC 沿着其水平最优-无向运动轴具有空间移位的谷氨酸能感受野。这种移位的感受野有助于在中断的运动轨迹中产生 DSGC 无向峰电位。理论分析表明,在中断运动期间的群体反应可能有助于 On-Off DSGC 群体在复杂的自然视觉环境中信号运动物体的空间位置。我们的研究强调,方向选择性电路在不同的刺激条件下利用了不同的机制,这些机制可能有助于编码多种视觉特征。