Fig. 5

Differential phenotypes of netrin-G1 KO and netrin-G2 KO mice in attention behaviors. a and b Home cage activity (netrin-G1 KO, 6-mo old, netrin-G2 KO, 3 mo-old): All mice were entrained under a 12-h dark and 12-h light cycle and their locomotor activities were recorded over 7 days. The circadian rhythm of the netrin-G KO mice did not appear to be grossly deviant from that of the WT mice. Average amounts of both horizontal (a) and vertical activity (b) over 6 days (days 2–7) were calculated in 1-h time bins for all genotypes (a.u. represents arbitrary unit; 2-way mixed ANOVA). Netrin-G1 KO mice were characterized by less vertical activity, representing attention behavior during the active phase, and hyperactivity during the late resting phase, indicating alterations in sleep. Netrin-G2 KO mice showed significantly decreased vertical activity, suggesting alterations in attention. c-f Attention-related behaviors were assessed by 5CSRTT (netrin-G1-KO and netrin-G2 KO, 7 mo-old at the beginning): c Netrin-G1 KO mice tended to make omission errors although there was no statistical significance (2-way mixed ANOVA for genotype, ns for interaction). d Netrin-G2, but not netrin-G1, KO mice exhibited increases in erroneous nose-poke numbers throughout the sessions (2-way mixed ANOVA for genotype, ns for interaction), indicating attention deficits. e Netrin-G1 KO mice exhibited higher erroneous nose-poke rates per response in later sessions (2-way mixed ANOVA for genotype, ns for interaction, post-hoc t-test). f Both genotypes tended to show premature responses, reflecting impulsivity, more frequently than WT mice although there was no overall statistical significance (2-way mixed ANOVA for genotype, ns for interaction). Data are presented as mean ± SEM