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

Abstract

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 typeand 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.

Morphological and distributional properties of SMI‐32 immunoreactive ganglion cells in the rat retina

“…The SMI‐32 antibody has been widely used to identify alpha RGCs and subsets of SMI‐32 + RGCs have been studied thoroughly (Bleckert et al., 2014 ; Okigawa et al., 2020 ; Schmidt et al., 2014 ; Sonoda et al., 2020 ). The RGC ON‐sustained subset, which can be labeled with SMI‐32, was reported to display a nasal‐to‐temporal gradient in cell density (Bleckert et al., 2014 ).…”

“…SMI‐32 antibodies were first generated to label cortical neurons (Ang et al., 1991 ; Campbell & Morrison, 1989 ; Sternberger & Sternberger, 1983 ), but they are now widely used to identify all populations of alpha RGCs (Bleckert et al., 2014 ; Krieger et al., 2017 ; Okigawa et al., 2020 ; Schmidt et al., 2014 ; Sonoda et al., 2020 ). The distribution of several SMI‐32 + RGCs subsets has been studied in detail in rodents.…”

Individual thalamic inhibitory interneurons are functionally specialized towards distinct visual features

“…Previous studies have indicated a dorsoventral gradient from superficial to deeper dLGN for direction-selective retinal ganglion cell projections (Kay et al, 2011; Kim et al, 2008; Krahe et al, 2011; Martersteck et al, 2017; Okigawa et al, 2021; Rivlin-Etzion et al, 2011), as well as an overrepresentation of direction/orientation-selective responses in the dorsolateral dLGN (Piscopo et al, 2013; Román Rosón et al, 2019), in particular an overrepresentation of horizontal motion in the superficial dLGN (Marshel et al, 2012). Therefore, we asked whether dLGN interneuron specialization is also dependent on depth.…”

Posteromedial cortical networks encode visuomotor prediction errors.

“…The jGCaMP7f fragment was generated using PCR with PrimeSTAR Max DNA Polymerase (TaKaRa, Shiga, Japan) on a PCR thermal cycler (TP350, TaKaRa) 57,58 . The plasmids were digested with appropriate restriction enzymes (New England BioLabs, Ipswich, MA, USA) under optimal conditions.…”

“…Brains were post-fixed with 4% PFA in PBS, 15% sucrose in PBS overnight, and then with 30% sucrose in PBS. The brains were subjected to histological analysis 57,60 Cryoprotected samples were sectioned at a thickness of 40 µm on a freezing microtome (REM-710, Yamato Kohki). The sections were rinsed with PBS, blocked for 1−2 h in a blocking solution (50% Blocking One (Nacalai, 03953-95) in 0.1% Triton X-100/PBS (PBST)), and then incubated overnight at 4℃ with primary antibodies: rabbit anti-GFP (1:3000, Abcam, cat# ab6556), chicken anti-GFP (1:2000, Abcam, cat# ab13970), goat anti-PV (1:500, Swant, cat# PVG-213), rat anti-SOM (1:500, Millipore, cat# MAB354), and rabbit anti-VIP (1:400, ImmunoStar, cat# 20077) in 5% Blocking One/0.1% PBST.…”