Extended Data Fig. 5: Remodeling of RGC axon arbors and periventricular interneuron (PVIN) dendrites after late OPC NTR ablation.
From: Oligodendrocyte precursor cells sculpt the visual system by regulating axonal remodeling
a) Schematic of experimental paradigm used in this figure. b-c) Confocal images of individual RGC axon arbor in control and OPC NTR ablation animals. Tracing reveals stable, added, and eliminated processes (n numbers as in panel d). Scale bar: 10µm. d) Quantification showing RGC arbor length reduction, eliminated and added processes; Boxes represent the median (center line) and I.Q.R. (left:16.0 ± 5.5/24.1% in control vs. 6.6 ± 1.5/10.9% in OPC NTR ablation; middle: 42.1 ± 34.0/45.7% vs. 33.3 ± 24.4/40.4%; right: 18.4 ± 13.3/27.9% vs. 16.2 ± 9.8/31.9%), and whiskers indicate the minimum and maximum values; unpaired two-tailed t-test, left: t=2.278, d.f.=24; middle: t=2.652, d.f.=24; right: t=0.288, d.f.=24; n=13 cells per group in 12/10 animals in control/OPC NTR ablation from four experiments). e) Example image showing that pre-synapses of PVIN localize to deeper layers of tectal neuropil marked by Tg(isl2b:EGFP) labelling all RGC axons (two biological / one technical replicate). Scale Bar: 50µm. f) Example image of individual PVIN co-labelled using foxp2a:tagCFP to outline cell morphology and pre-synapse marker to reveal its axon (three biological / one technical replicate). Scale bar: 10 µm. g-i) Confocal images and rotation views of individual PVIN at two timepoints in control animals (g) and in OPC ablated animals (h) (n numbers as in panel j). Traces show dendritic processes analyzed in panel i. Scale bars: 10µm. j) Quantifications of dendritic PVIN arbor remodeling between 7-10dpf in control and OPC NTR ablation animals showing no significant changes in total dendritic length, eliminated and added processes number; n=12 cells in 12 animals in control and n=12 cells in 10 animals in OPC NTR from five experiments (left: mean 5.1±7.9 S.D. in control vs. 4.2 ± 7.0 in OPC NTR ablation; middle: 15.4 ± 6.0 vs. 15.5±6.6; right: 11.8±5.5 vs. 11.5 ± 3.1; unpaired two-tailed t test, left: t=0.305, d.f.=21.68; middle: t=0.007, d.f.=21.84; right: t=0.157, d.f.=17.52).
