Fig 2. Anxiety-like behavior in the elevated plus maze test.

Boxplots show the results of anxiety-like behavior in the elevated plus maze test (EPM). Young (3 months) and old (≥18 months) α-GAL A deficient (Fabry KO) and wildtype littermate (WT) male mice were investigated in the naïve state and after i.pl. complete Freund`s adjuvant (CFA) injection into the right hind paw. A) Time spent in the open arms was not different between naïve genotypes and age-groups, except for young WT mice compared to young Fabry KO mice (p<0.05). I.pl. CFA injection led to a decrease of time spent in the open arms in young Fabry KO mice compared to young naïve Fabry KO mice (p<0.05). After CFA injection time spent in open arms was also lower in young Fabry KO mice than in young WT mice (p<0.05). In old mice CFA i.pl. reduced time spent in open arms in Fabry KO (p<0.01) and WT mice (p<0.05). B) There was no intergroup difference in the number of entries into the open arms in naïve and CFA treated mice except for old CFA treated Fabry KO mice, which entered less often than old naïve Fabry KO mice (p<0.05). C) No difference was found in young age-groups for time spent in closed arms. Old CFA treated mice of both genotypes spent more time in the closed arms compared to old naive mice (Fabry KO: p<0.01; WT: p<0.001). D). There was no difference in entries into the closed arms between age-groups and genotypes in the naïve state. After CFA injection young Fabry KO mice more often entered the closed arms than young WT mice (p<0.05). Also, old CFA treated Fabry KO mice had more entries into the closed arm than old naïve mice (p<0.05). Fabry KO: young (3 months; naïve: 10 male; CFA: 6 male), old (≥18 months; naïve: 10 male; CFA: 6 male). WT: young (3 months; naïve: 10 male; CFA: 6 male), old (≥18 months; naïve: 10 male; CFA: 6 male). *p<0.05, **p<0.01.