Data are from the same experimental groups described in Fig. 3, except that here we directly compare saline/vehicle to saline/L-NAME rats (A,B) and cocaine/vehicle to cocaine/L-NAME rats (C,D). In saline pretreated rats, L-NAME treatment during withdrawal had no effect in core (A) or shell (B). L-NAME treatment during withdrawal had no significant effects in the core (C) of sensitized rats. However, in the NAc shell of cocaine-sensitized rats (D), L-NAME treatment during withdrawal reduced surface GluA1 (t18=2.25, *P<0.05) and surface stargazin (t17=2.29, *P<0.05) as compared to cocaine-sensitized rats treated with vehicle during withdrawal (Student's t-tests comparing cocaine/vehicle versus cocaine/L-NAME groups).