Figure 6. Response Selectivity of DSGCs Is Enhanced in Amigo2 KO Retinas.

(A) Grayscale plots of the DSGC responses in wild-type (left panel) and Amigo2 KO (right panel) mice to drifting grating stimuli. Each row depicts average responses of one cell to 0.023–0.034 cycles per degree (cpd) gratings drifting at 1–2 cycles s⁻¹ (wild-type: n = 46 cells, n = 6 retinas; Amigo2 KO: n = 40 cells, n = 8 retinas). Responses of each cell were centered on the direction eliciting the maximal response and its highest-response neighbor.

(B) Summary data (mean ± SEM) of DSGC responses in (A) for wild-type (left panel) and Amigo2 KO (right panel) mice.

(C) Responses of DSGCs (mean ± SEM) to null-direction drifting grating stimuli of varying temporal (left panel) and spatial (right panel) frequencies in wild-type (n = 46 cells, n = 6 retinas) and Amigo2 KO (n = 40 cells, n = 8 retinas) mice. Null-direction firing rates tended to be lower in Amigo2 KO compared to wild-type mice, but this trend did not reach statistical significance; p = 0.39 (left panel) and p = 0.52 (right panel) by bootstrapping.

(D) Responses of DSGCs (mean ± SEM) to preferred-direction drifting grating stimuli of varying temporal (left panel) and spatial (right panel) frequencies in wild-type (n = 46 cells, n = 6 retinas) and Amigo2 KO (n = 40 cells, n = 8 retinas) mice. Preferred-direction firing rates tended to be higher in Amigo2 KO compared to wild-type mice, but this trend did not reach statistical significance; p = 0.15 (left panel) and p = 0.056 (right panel) by bootstrapping.

(E) Direction selectivity indices (DSIs; mean ± SEM) of DSGC responses to drifting grating stimuli of varying temporal (left panel) and spatial (right panel) frequencies in wild-type (n = 46 cells, n = 6 retinas) and Amigo2 KO (n = 40 cells, n = 8 retinas) mice. DSIs were consistently higher in Amigo2 KO compared to wild-type mice; p = 0.0032 (left panel) and p = 0.0085 (right panel) by bootstrapping.

(F and G) Spatiotemporal receptive field maps (left panels) and static nonlinearities (right panels) of representative ON (F) and OFF (G) ganglion cells in wild-type (top panels) and Amigo2 KO (bottom panels) mice.

(H) Cumulative distributions of time to peak sensitivity (left panel) and peak firing rates (right panel) of ON ganglion cells in wild-type (n = 143 cells, n = 5 retinas) and Amigo2 KO (n = 156 cells, n = 6 retinas) mice; p = 0.94 for time to peak sensitivity and p = 0.54 for peak firing rates by bootstrapping.

(I) Cumulative distributions of time to peak sensitivity (left panel) and peak firing rates (right panel) of OFF ganglion cells in wild-type (n = 185 cells, n = 5 retinas) and Amigo2 KO (n = 233 cells, n = 6 retinas) mice; p = 0.67 for time to peak sensitivity and p = 0.59 for peak firing rates by bootstrapping.

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

See also Figures S3 and S6.