Summary of the potency of nicotine in male and female mice in different behavioral tests.

ED50 values (±CL) were calculated from the dose-response curve of the different groups and expressed as mg/kg.Animals were pretreated with either vehicle or menthol (100 mg/kg, i.p.) followed by nicotine (2.5 mg/kg s.c.) at different doses and then tested 5 min (tail-flick and hot-plate tests) or 20 min later (hypothermia). Each point represents the mean ± SE of 6 to 8 mice.