Department of Biology, University of Victoria, Victoria, BC V8P 5C2, Canada.
Department of Biology, University of Victoria, Victoria, BC V8P 5C2, Canada.
Cell Rep. 2022 Feb 22;38(8):110412. doi: 10.1016/j.celrep.2022.110412.
A neuron's ability to perform parallel computations throughout its dendritic arbor substantially improves its computational capacity. However, during natural patterns of activity, the degree to which computations remain compartmentalized, especially in neurons with active dendritic trees, is not clear. Here, we examine how the direction of moving objects is computed across the bistratified dendritic arbors of ON-OFF direction-selective ganglion cells (DSGCs) in the mouse retina. We find that although local synaptic signals propagate efficiently throughout their dendritic trees, direction-selective computations in one part of the dendritic arbor have little effect on those being made elsewhere. Independent dendritic processing allows DSGCs to compute the direction of moving objects multiple times as they traverse their receptive fields, enabling them to rapidly detect changes in motion direction on a sub-receptive-field basis. These results demonstrate that the parallel processing capacity of neurons can be maintained even during periods of intense synaptic activity.
神经元在其树突分支中进行并行计算的能力极大地提高了其计算能力。然而，在自然的活动模式下，计算的分区程度尚不清楚，特别是在具有活跃树突的神经元中。在这里，我们研究了运动物体的方向如何在小鼠视网膜中的 ON-OFF 方向选择性神经节细胞（DSGC）的双分层树突分支中进行计算。我们发现，尽管局部突触信号在其树突分支中有效传播，但树突分支的一部分中的方向选择性计算对其他部分的计算几乎没有影响。独立的树突处理使 DSGC 能够在它们的感受野中多次计算运动物体的方向，从而使它们能够快速检测运动方向的变化，这是基于亚感受野的。这些结果表明，即使在强烈的突触活动期间，神经元的并行处理能力也可以保持。
