Fig. 4.

Mean (±S.E.M.) responses per 10-minute block during the 1^st relapse session on the EtOH lever by P rats given i.p. saline (n = 4/time point) or 1 or 10 mg/kg of cocaine (n = 7– 8/dose/time point) immediately, 30 minute or 4 hour prior to only the session. Upper Panel: (*) indicates that rats administered 1 mg/kg cocaine immediately prior to the relapse test responded significantly (p < 0.05) less on the EtOH lever during 1^st and 2^nd 10-minute block compared to all other groups, and the group given cocaine 4 hour prior to the session increased EtOH responding during 4^th and 6^th 10-minute block compared to saline values. Lower Panel: (*) indicates that rats (a) administered 10 mg/kg cocaine immediately prior to the session responded significantly (p < 0.05) less on the EtOH lever during the 1^st 10-minute block compared to all the other groups; (b) administered 10 mg/kg cocaine immediately or 4 hour prior to the session had lower responding compared to other 2 groups during the 2^nd 10-minute block; (c) 10 mg/kg cocaine given 30-minute prior to relapse testing increased EtOH responding significantly more compared to saline during the 1^st, 2^nd, and 3^rd 10-minute block ; and (d) 10 mg/kg cocaine given 4 hour prior to session increased EtOH responding during the 5^th and 6^th 10-minute block compared to saline.