Laboratory of Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan.
Laboratory of Neural Information Processing, Institute for Advanced Research, Nagoya University, Nagoya, Japan.
J Comp Neurol. 2021 Jun;529(8):2099-2124. doi: 10.1002/cne.25075. Epub 2020 Dec 2.
Over 40 distinct types of retinal ganglion cells (RGCs) generate parallel processing pathways in the visual system. In mice, two subdivisions of the dorsal lateral geniculate nucleus (dLGN), the core and the shell, organize distinct parallel channels to transmit visual information from the retina to the primary visual cortex (V1). To investigate how the dLGN core and shell differentially integrate visual information and other modalities, we mapped synaptic input sources to each dLGN subdivision at the cell-type level with G-deleted rabies viral vectors. The monosynaptic circuit tracing revealed that dLGN core neurons received inputs from alpha-RGCs, Layer 6 neurons of the V1, the superficial and intermediate layers of the superior colliculus (SC), the internal ventral LGN, the lower layer of the external ventral LGN (vLGNe), the intergeniculate leaf, the thalamic reticular nucleus (TRN), and the pretectal nucleus (PT). Conversely, shell neurons received inputs from alpha-RGCs and direction-selective ganglion cells of the retina, Layer 6 neurons of the V1, the superficial layer of the SC, the superficial and lower layers of the vLGNe, the TRN, the PT, and the parabigeminal nucleus. The present study provides anatomical evidence of the cell type- and layer-specific convergence in dLGN core and shell neurons. These findings suggest that dLGN core neurons integrate and process more multimodal information along with visual information than shell neurons and that LGN core and shell neurons integrate different types of information, send their own convergent information to discrete populations of the V1, and differentially contribute to visual perception and behavior.
超过 40 种不同类型的视网膜神经节细胞 (RGCs) 在视觉系统中产生并行处理途径。在小鼠中，外侧膝状体核 (dLGN) 的两个亚区，核心和壳，组织了不同的平行通道，将视觉信息从视网膜传递到初级视觉皮层 (V1)。为了研究 dLGN 核心和壳区如何差异整合视觉信息和其他模态，我们使用 G 缺失型狂犬病毒载体在细胞类型水平上绘制了每个 dLGN 亚区的突触输入源。单突触回路追踪显示，dLGN 核心神经元接收来自 alpha-RGCs、V1 的第 6 层神经元、上丘的浅层和中间层、内侧膝状体核、外侧膝状体核的浅层和中层 (vLGNe)、中脑间核、丘脑网状核 (TRN) 和顶盖前核 (PT) 的输入。相反，壳区神经元接收来自 alpha-RGCs 和视网膜方向选择性神经节细胞、V1 的第 6 层神经元、上丘的浅层、vLGNe 的浅层和中层、TRN、PT 和对侧旁正中核的输入。本研究提供了 dLGN 核心和壳区神经元在细胞类型和层特异性汇聚的解剖学证据。这些发现表明，dLGN 核心神经元比壳区神经元整合和处理更多的多模态信息以及视觉信息，并且 LGN 核心和壳区神经元整合不同类型的信息，将自己的会聚信息发送到 V1 的离散群体，并差异地贡献于视觉感知和行为。
