Fig. 4

Effect of TEMPOL on nicotine self-administration in rats. (A). Experimental schedule. Saline or TEMPOL (50 mg/kg, i.p.) was injected 10 min before the beginning of the nicotine self-administration test on the test day. (B). Representative pattern of nicotine infusion during a 1 h session of the nicotine self-administration test after pretreatment with saline or TEMPOL. C-E. Mean number of infusions (C) and active (D) and inactive (E) lever presses over 1 h of the nicotine self-administration test after pretreatment with saline or 50 mg/kg TEMPOL. *P < 0.05 or **P < 0.01 vs. the saline control group. n = 6/group. All the values are presented as the mean ± SD.