PDF(Pubmed)
Abstract：
VGluT3-expressing mouse retinal amacrine cells (VG3s) respond to small-object motion and connect to multiple types of bipolar cells (inputs) and retinal ganglion cells (RGCs, outputs). Because these input and output connections are intermixed on the same dendrites, making sense of VG3 circuitry requires comparing the distribution of synapses across their arbors to the subcellular flow of signals. Here, we combine subcellular calcium imaging and electron microscopic connectomic reconstruction to analyze how VG3s integrate and transmit visual information. VG3s receive inputs from all nearby bipolar cell types but exhibit a strong preference for the fast type 3a bipolar cells. By comparing input distributions to VG3 dendrite responses, we show that VG3 dendrites have a short functional length constant that likely depends on inhibitory shunting. This model predicts that RGCs that extend dendrites into the middle layers of the inner plexiform encounter VG3 dendrites whose responses vary according to the local bipolar cell response type.
摘要：
表达VGluT3的小鼠视网膜无长突细胞（VG3s）响应小物体运动，并连接到多种类型的双极细胞（输入）和视网膜神经节细胞（RGCs，输出)。因为这些输入和输出连接在相同的枝晶上混合，要理解VG3电路，需要将突触在其骨架上的分布与信号的亚细胞流进行比较。这里,我们结合亚细胞钙成像和电子显微镜连接组重建来分析VG3s如何整合和传递视觉信息。VG3s接收来自所有附近双极细胞类型的输入,但表现出对快速3a型双极细胞的强烈偏好。通过将输入分布与VG3枝晶响应进行比较，我们表明VG3树突具有短的功能长度常数，这可能取决于抑制性分流。该模型预测，将树突扩展到内部丛状中间层的RGC会遇到VG3树突，其响应根据局部双极细胞响应类型而变化。
