Efffects of vigabatrin on spontaneous locomotor activity of rats

Abstract

AbstractEffects of vigibatrin (saline, 125, 250, or 500 mg/kg i.p.) on spontaneous locomotor activity in Wistar rats were investigated. There was a dose dependent decrease in amount of locomotion for doses up to 250 mg/kg. This decrease was measurable 2–4 hours after injection and still became more pronounced in the following hours. The mean velocity during the movements 2–6 hours after injection remained intact and was higher in the 500 mg/kg group. In this high dose group an abnormal posture with a hunched back and pilo‐erection was observed. The decrease of the amount of motor activity with the preservation of the mean velocity in this non‐stimulating procedure, suggests that the level in which the experimental procedure imposes motor activity might be an important factor when measuring effects of vigabatrin. Postscript: Immediate post injection effects were observed, equivalent to those seen in the writhing test, a pain test using hyperosmolar saline injections. These observations stress the importance of controlling the osmolarity of the injection fluids.