Fig. 2

Differential phenotypes of netrin-G1 KO and netrin-G2 KO mice in sensorimotor behaviors. a and b Optometry: a Visual acuity in both left and right eyes was examined by measuring the highest spatial frequency the mouse could track when the grating was systematically increased. Visual acuity was comparable between netrin-G1 KO mice and WT mice [2–3 mo-old, two-way ANOVA for genotype, not significant (ns) for interaction between factors]. Netrin-G2 KO mice exhibited decreased visual acuity (4–6 mo-old, two-way ANOVA for genotype, ns for interaction). b Visual contrast sensitivity was evaluated by measuring the minimum contrast that could induce tracking behavior at six different spatial frequencies. Netrin-G1 KO mice showed a modest increase in contrast sensitivity (two-way ANOVA for genotype, ns for interaction). Contrast sensitivity was comparable between netrin-G2 KO mice and WT mice (two-way ANOVA for genotype, ns for interaction). c Visual perception of depth was examined using a visual cliff test. Netrin-G1 KO and WT mice did not differ in the time spent on the platform or on visual cliff areas (10 mo-old, Student’s t-test). Netrin-G2 KO mice spent more time in the visual cliff area (9 mo-old, Student’s t-test). d and e ABR: d Sample traces of the ABR. e Amplitude analysis of the wave peaks revealed no effect of deletion of the netrin-G1 gene (6 mo-old, two-way mixed ANOVA for genotype, ns for interaction in all analyses). In netrin-G2 KO mice, on the other hand, peaks 2 and 3 were significantly reduced (8 mo-old, two-way mixed ANOVA for genotype, ns for interaction in all analyses), while peak 1 was not affected by genotype. f Startle responses to auditory stimuli. Netrin-G1 KO mice did not differ from WT mice in their startle response to the auditory stimuli (3 mo-old, mixed two-way ANOVA for genotype, ns for interaction). Netrin-G2 KO mice, however, exhibited marked deficits (4 mo-old, two-way mixed ANOVA for genotype, significant interaction; * P < 0.05, ** P < 0.01, **** P < 0.0001, post hoc t-test). g Responses to electric foot shocks: netrin-G1 KO and netrin-G2 KO mice did not differ from WT mice in sensitivity to electric foot shocks (netrin-G1 KO, 8–9 mo-old, netrin-G2-KO, 10 mo-old; two-way ANOVA for genotype, ns for interaction in both genotypes). h Rotarod test: The latencies to fall off the accelerating rotarod task were compared to evaluate motor learning and coordination ability. Netrin-G1 KO remained on the rotating rod for a longer time than WT mice (2–3 mo-old; mixed two-way ANOVA for genotype, ns for interaction). Netrin-G2 KO mice remained on the rod for a shorter time (5 mo-old; two-way mixed ANOVA for genotype, ns for interaction). i Hanging wire test: There was no genotype difference between netrin-G1 KO and WT mice (4–5 mo-old, Student’s t-test). Netrin-G2 KO mice remained on the wire for a shorter time (5 mo-old, Student’s t-test). Data are presented as mean ± SEM