Fig. 7. Nicotine exposure only during adolescence confers persistent sensitization to the ambulatory activity-increasing effects of a single adulthood nicotine challenge, compared to nicotine exposure only during adulthood.
Distance traveled in the 1 hour following a final nicotine challenge of 0.5 mg/kg for all rats (n = 5–7 per group). This challenge was given 1 week after the conclusion of the 2-week adulthood locomotor activity study. Panel a) shows rats that received saline during adulthood, so that their only nicotine exposure prior to the challenge was during adolescence (adolescent treatments indicated on x-axis). Panel b) shows rats that received saline during adolescence, so that their only nicotine exposure prior to the challenge was during adulthood (adult treatments indicated on x-axis). Values are given as mean ± SEM. * Indicates significant (p < 0.05) difference from saline group.