Northwestern University Interdepartmental Neuroscience Graduate Program, Chicago, IL, USA.
Departments of Ophthalmology and Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
Nat Neurosci. 2021 Jan;24(1):105-115. doi: 10.1038/s41593-020-00747-8. Epub 2020 Nov 23.
In the vertebrate retina, the location of a neuron's receptive field in visual space closely corresponds to the physical location of synaptic input onto its dendrites, a relationship called the retinotopic map. We report the discovery of a systematic spatial offset between the ON and OFF receptive subfields in F-mini-ON retinal ganglion cells (RGCs). Surprisingly, this property does not come from spatially offset ON and OFF layer dendrites, but instead arises from a network of electrical synapses via gap junctions to RGCs of a different type, the F-mini-OFF. We show that the asymmetric morphology and connectivity of these RGCs can explain their receptive field offset, and we use a multicell model to explore the effects of receptive field offset on the precision of edge-location representation in a population. This RGC network forms a new electrical channel combining the ON and OFF feedforward pathways within the output layer of the retina.
在脊椎动物的视网膜中，神经元在视觉空间中的感受野位置与突触输入到其树突的物理位置密切对应，这种关系称为视网膜映射。我们报告了 F-迷你 ON 视网膜神经节细胞（RGC）中 ON 和 OFF 感受野亚区之间存在系统性空间偏移的发现。令人惊讶的是，这种特性不是来自于空间上偏移的 ON 和 OFF 层树突，而是来自于通过缝隙连接到不同类型的 F-迷你 OFF RGC 的电突触网络。我们表明，这些 RGC 的不对称形态和连接性可以解释它们感受野的偏移，我们使用一个多细胞模型来探索感受野偏移对群体中边缘位置表示精度的影响。这个 RGC 网络形成了一个新的电通道，将视网膜输出层中的 ON 和 OFF 前馈通路结合在一起。
