| Abstrakt: |
Objectives Ketamine has been reported to have antidepressant effects or psychotomimetic effects. The aim of this study was to investigate the behavioral effects of ketamine treatment at various sub-anesthetic doses in adolescent and adult naïve mice. Methods In each experiment for adolescent and adult mice, a total of 60 male Institute of Cancer Research mice were randomly divided into 6 groups, which were intraperitoneally treated with physiological saline, 10, 20, 30, 40, and 50 mg/kg ketamine for consecutive 3 days. At 1 day after last injection, the locomotor and depressive-like behaviors were evaluated in mice, using open field test (OFT) and forced swim test (FST), respectively. Results In case of adolescent mice, ketamine dose was negatively correlated with total distance traveled in the OFT (Spearman’s rho = -0.27, p = 0.039). In case of adult mice, we found significant positive correlation between ketamine dose and duration of immobility in the FST (Spearman’s rho = 0.45, p < 0.001). Immobility time in the 50 mg/kg ketamine-treated mice was significantly higher compared to the saline-treated mice (Dunnett’s post-hoc test, p = 0.012). Conclusions We found that the repeated treatment with ketamine could decrease the locomotor or prolong the duration of immobility in mice as the dose of ketamine increased. Our findings suggest that sub-anesthetic doses of ketamine might induce schizophrenia- like negative symptoms but not antidepressant effects in naïve laboratory animals. [ABSTRACT FROM AUTHOR] |
