Naloxone specifically blocks the linear locomotion in mice. 
The effects of naloxone on mouse behavior were investigated by using a multi-dimensional behavioral analyzer.  No significant changes in behavior were seen after 1, 3 and 10 mg/kg doses of naloxone.  Within 15 min following the start of observation, however, naloxone significantly suppressed linear locomotion at the 30 mg/kg dose, while the same dose of naloxone did not markedly affect other behaviors such as rearing and grooming.  These results suggest that naloxone specifically disrupts linear locomotion in the mouse.