Figure 5. Asymmetric Connectivity between SACs and DSGCs in Wild-Type and Amigo2 KO Mice.

(A) Maximum intensity projection of a two-photon image stack acquired at the end of a paired recording from a DSGC and a null-side SAC in a ChAT-Cre Ai9 DRD4-EGFP mouse on a wild-type background.

(B) Representative inhibitory postsynaptic currents (IPSCs) elicited in DSGCs by depolarizing SACs on the null (top trace) and preferred side (bottom trace) in a wild-type background.

(C and D) Summary data (mean ± SEM) comparing the inhibitory conductances activated in DSGCs by stimulation of SACs on the null versus preferred side (C; null side: 6.0 ± 1.9 nS, n = 6 pairs, n = 4 retinas; preferred side: 0.47 ± 0.20 nS n = 4 pairs, n = 4 retinas; p = 0.0095 by Mann-Whitney U test) and the soma-soma distance of SAC-DSGC pairs (D, null side: 78 ± 9.2 μm; preferred side: 78 ± 13 μm; p = 0.91 by Mann-Whitney U test) in a wild-type background.

(E) Maximum intensity projection of a two-photon image stack acquired at the end of a paired recording from a DSGC and a null-side SAC in a ChAT-Cre Ai9 DRD4-EGFP mouse on an Amigo2 KO background.

(F) Representative IPSCs elicited in DSGCs by depolarizing SACs on the null (top trace) and preferred side (bottom trace) in an Amigo2 KO background.

(G and H) Summary data (mean ± SEM) comparing the inhibitory conductances activated in DSGCs by stimulation of SACs on the null versus preferred side (G; null side: 4.0 ± 1.3 nS, n = 7 pairs, n = 4 retinas; preferred side: 0.26 ± 0.15 nS, n = 6 pairs, n = 4 retinas; p = 0.0012 by Mann-Whitney U test) and the soma-soma distance of SAC-DSGC pairs (H; null side: 94.7 ± 8.6 μm; preferred side: 90 ± 13 μm; p = 1 by Mann-Whitney U test) in an Amigo2 KO background. Inhibitory conductances activated by stimulation of individual null-side SACs were not significantly different between wild-type and Amigo2 KO backgrounds (p = 0.37).

Throughout the figure, **p < 0.01 and ns indicates no significant differences for statistical comparisons.