Locomotor activity following METH (CS+, black symbols) and saline (CS−, white symbols) is shown for the conditioning (a), extinction (b), and reconditioning trials (c). During conditioning trial 1, lesioned subjects (n = 11; squares) were more active than sham subjects (n = 23; triangles) following saline or METH (*** p < 0.001). Additionally, across all conditioning trials, sham and lesioned subjects were more active following IP METH compared to saline (* p < 0.05). During extinction trials, sham subjects (n = 22) were more active on trial 1 than trials 2, 3, 4, 5 and 6 (** p < 0.01), and lesioned subjects were more active on trials 1 and 2 than trials 2 and 5, respectively (* p < 0.05). During the reconditioning trials, IP METH increased locomotor activity in sham (n = 22) and lesioned subjects (n = 11) compared to saline (*** p < 0.0001).