Cell type‐ and layer‐specific convergence in core and shell neurons of the dorsal lateral geniculate nucleus

• Published in: Journal of comparative neurology (1911) Vol. 529; no. 8; pp. 2099 - 2124
• Main Authors: Okigawa, Sayumi, Yamaguchi, Masahiro, Ito, Kei N., Takeuchi, Ryosuke F., Morimoto, Nao, Osakada, Fumitaka
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.06.2021; Wiley Subscription Services, Inc
• Subjects: Animals; Convergence; core; Female; Geniculate Bodies - cytology; Information processing; Lateral geniculate nucleus; Male; Mice; Neurons; Neurons - cytology; Pretectal nuclear complex; Rabies; Retina; Retinal ganglion cells; shell; Superior colliculus; Thalamic reticular nucleus; Thalamus; trans‐synaptic tracing; Visual cortex; Visual Pathways - cytology; Visual perception; Visual system; visual system; trans-synaptic tracing; core; shell; lateral geniculate nucleus
• ISSN: 0021-9967; 1096-9861
• DOI: 10.1002/cne.25075

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. Rabies virus‐based monosynaptic circuit tracing allows the exploration of cell‐type specificity of both long‐distance and local connections in the central nervous system. We provide 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 dLGN 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.