Exploration And Anxiety Related Behavioural Analysis On FMR-1 Knockout Mice

[Objective]To observe the exploration and anxiety related behavior of the fragile X mouse model, FMR-1 gene knockout mice, is looking for the behavioral characterization of KO mice and the differences between phenotype of fragile X syndrome. For the purpose of asking the right form of education and further studying the molecular mechanism of the disease.[Methods]There were three behavioral studies used, the open field test, the elevated plus maze test and the light/dark box test.21-day-old FMR-1 knockout male mice (KO group) were compared to their littermates which were wild-type male mice (WT group) with respect to their exploration and anxiety related behavior in the behavioral studies. Data were analyzed by t-tests.[Results]All data were analyzed by using the SPSS 17.0:In the open field, compared to the WT group, the number of line crossings in KO mice increased significantly (P<0.01), with the motoricity raising (P< 0.05); Meanwhile, KO mice had more central-area entries and spend more time in the central area (P< 0.05); however, there were no differences in the number of standing upright on hind legs and the percent of central-area motoricity (P> 0.05).In the elevated plus maze test, compared to WT group, the total arm entries in KO mice decreased significantly (P<0.05) and the percent of open-arm time grew (P<0.05); No differences were found in the percent of open-arm entries (P> 0.05). In the light/dark box test, compared to WT group, the percent of time spent in the lit compartment and the number of transitions between compartments in KO mice increased significantly (P<0.05)[Conclusions]FMR-1 knockout mice exhibited increased locomotor activity and increased excitability; Meanwhile, they showed poor ability of visual spatial skills. These behavioral characterizations were parallel with the phenotype of fragile X syndrome, who had hyperactivity and visual-spatial cognitive dysfunction. Contrary to expectations,FMR-1 knockout mice showed decreased anxiety-like behavior in the behavioral studies, which was inconsistent with the phenotype of fragile X syndrome.