Figure 3:

Latency to self-administer remifentanil within the punished context increased as a function of foot-shock punishment but less so in nicotine-treated rats. (A) There was no difference in latency to first infusion in the unpunished context, and latency in the unpunished context was not affected by punishment in the alternate context. (B) Saline-treated rats reliably increased their latency to first RMF infusion following conditioning with 0.4 mA foot-shock, while nicotine-treated rats did not do so until the final conditioning session. Additionally, nicotine-treated rats were significantly faster than saline-treated rats to earn their first infusion during the final conditioning session (0.6 mA). (C) Similarly, compared to nicotine-treated rats, saline-treated rats reliably increased their latency to first earned punisher following conditioning with 0.4 mA foot-shock, while nicotine-treated rats did not do so until the final conditioning session. Nicotine-treated rats were significantly faster than saline-treated rats to earn their first punisher during final two conditioning sessions. *s indicate significant group differences (P < 0.05).