The effects of nicotine on locomotor behavior in non-tolerant rats: a multivariate assessment.

Previous studies assessing the effects of nicotine on the locomotion of non-tolerant rats have yielded mixed results. High doses of nicotine have been reported to decrease both rearing and locomotor behavior. Low doses of nicotine have either decreased or had no effect on rearing, and have been reported to increase, decrease or have no effect on ambulation. The present study utilized ten indices of locomotor behavior collected simultaneously, which allowed for a more fine-grained analysis of locomotor behavior than has been possible previously. The results indicated that nicotine decreased measures of vertical movement (rearing) in a dose-related fashion. Measures of ambulation revealed a more complex pattern: the number of movements increased in a dose-dependent fashion, while average speed of movement exhibited a dose-related decrease. The present results may help to explain the disparate results reported by earlier investigators.