Fig. 4: Depth-dependent inhibitory effects of vLGN input to SC.

a Schematic of experimental setup. b Example electrode track (top) and expression of ChR2-EYFP in vLGN (bottom). Scale bar, 500 μm. n = 3 replicates. c Example heatmap for SC responses to a flashing dark disk (top inset) across different channels. d Heatmap for current source density in the same recording. Red dash line marks the boundary between SGS and SO. e Spontaneous spikes responding to the optogenetic activation alone. f PSTHs for spontaneous spikes responding to the optogenetic activation in two example neurons. g PSTHs for spike responses responding to a flash dark disk without (left) and with (right) LED light pulses in the same neurons shown in (f). h Normalized visually evoked firing rate (FR) (left), and fold changes in spontaneous (middle) and evoked (right) spike rates by activating vLGN axons, at different SC depths. ****p < 0.0001, ***p < 0.001, **p < 0.01, two-tailed one sample t-test. Left-to-right, n = 176, 252, 182 neurons. i Schematic of recording in SC while photo-inhibiting vLGN neurons. j Fold changes in spontaneous (left) and evoked (right) spike rates at different depths. ****p < 0.0001, ***p < 0.001, **p < 0.01, *p < 0.05, two-tailed one sample t-test. Left-to-right, n = 185, 177 neurons. k RFs of two example neurons at different SC depths. l Average RF radius at different SC depths. ****p < 0.0001, ***p < 0.001, **p < 0.01, *p < 0.05, Kruskal–Wallis test and Dunn’s multiple comparison test. n = 112 neurons. m Schematic anterograde transsynaptic labeling of vLGN-recipient SC neurons. n TdTomato expression at the injection site. Scale bar, 500 μm. o Labeled vLGN-recipient neurons in SC. Scale bar, 500 μm. Right, enlarged boxed area. Scale bar, 100 μm. ZO zonal, SuG superficial gray, SO stratum opticum, InG intermediate gray, InWh intermediate white, DG deep gray. p Numbers of anterogradely labeled neurons in different SC sublayers. n = 5 sections from 3 mice. Data are presented as mean ± s.e.m. in (h, j, l and p). Source data are provided as a Source Data file.