Figure 2.
Systemic LY379268 injection decreased nicotine (A, black bars; n = 7, timeout 20 s) but not food self-administration, except at the highest LY379268 dose (A, white bars; n = 8, timeout 210 s). LY379268 injection into the NAc shell (B; n = 9) or the VTA (C; n = 9) decreased nicotine self-administration. Control injection of 1 μg of LY379268 2 mm above the NAc shell into the lateral septal nucleus had no effect on nicotine self-administration (B; Co, control injection; n = 9). Injection of 0.6 μg 2 mm above the VTA into the red nucleus had no effect on nicotine self-administration (C; Co, control injection; n = 7). Number of food pellets earned after systemic LY379268 (D; n = 8), intra-NAc shell (E; n = 9), or intra-VTA (F; n = 9) injection under the FR5 TO20 s schedule of reinforcement. *p < 0.05, **p < 0.01, ***p < 0.001, different from 0 mg/kg LY379268; +p < 0.05, different from 1 mg/kg LY379268. #p < 0.06, ##p < 0.001, different from control injection.