WOBE437 induced muscle
relaxation without sedative effects in male
C57BL/6 mice. (A) Muscle relaxation was evaluated using the Straub
test after morphine administration (40 mg/kg, s.c.). (B) Spontaneous
locomotion was evaluated in the open-field test (OFT) by placing each
mouse in the arena and allowing it to freely move for 5 min. (C) The
potential induction of catalepsy-like behavior was assessed in the
bar test. Vehicle (DMSO, n = 10), WOBE437 (10 mg/kg,
WOBE, n = 6), and WIN-55212-2 (3 mg/kg, WIN, n = 5) were injected (i.p.) 1 h before morphine injection.
Baclofen (5 mg/kg, n = 7) and/or diazepam (6 mg/kg,
DZP, n = 5) were injected (i.p.) 40 min before morphine
injection. Importantly, the OFT and the bar test were conducted just
before morphine administration: 8 and ∼2 min before, respectively.
Data show (A) cumulative frequency or (B, C) median, percentile 25,
percentile 75, minimum, and maximum. Statistical differences were
determined using (A) the chi-square test and Fisher’s exact
test or (B, C) the Kruskal–Wallis test followed by the Mann–Whitney
test as post hoc analysis. *, p < 0.05 compared
to vehicle group.