Skip to main content
. 2021 Jun 21;12:685631. doi: 10.3389/fphar.2021.685631

FIGURE 2.

FIGURE 2

Effects of repeated administration of sCT and nicotine on locomotor sensitisation in male mice (A) Repeated nicotine (Nic) administration (0.5 mg/kg, IP) for 5 days (D1-D5) increased locomotion in mice, when compared to vehicle (Veh) at days 4 and 5 of administration (*p < 0.05, **p < 0.01, for the Veh-Nic vs. Veh-Veh comparisons). Locomotor stimulation was lower at Day 3–5 in mice pre-treated with sCT (5 μg/kg, IP) prior to nicotine, compared to those pre-treated with vehicle (# p < 0.05, ## p < 0.01, for the Veh-Nic vs. sCT-Nic comparisons). There was no difference in nicotine locomotor response between the sCT-nicotine or vehicle-vehicle treated mice. sCT had no effect per se on locomotor activity at any day, when compared to the vehicle group (B) The difference of travelled distance between D5-D1 was higher in vehicle-nicotine treated mice compared to vehicle-vehicle treated mice (*p < 0.05, for the Veh-Nic vs. Veh-Veh comparisons). The D5-D1 difference of travelled distance was lower in the sCT-nicotine compared to vehicle-nicotine treated mice (# p < 0.05). There was no difference in locomotor response between vehicle-vehicle and sCT-nicotine treated mice (C) On Day 8 (D8), mice previously treated with vehicle-nicotine (Veh/Nic) during Day 1–5 (D1-5) showed higher locomotion response to a low dose of nicotine (Nic, 0.25 mg/kg, IP), compared to mice treated with sCT-nicotine (sCT/Nic) during D1-D5 (*p < 0.05). There was no difference in the locomotor activity response to a low dose of nicotine (Nic) between groups previously treated with vehicle-vehicle (Veh/Veh) or sCT-vehicle (sCT/Veh) during D1-D5. Data are presented as mean ± SEM.