The effects of STT or VPL lesions on the ulnar inhibition of cocaine locomotion. (A) STT lesions (STT X) at the C3 level of the spinal cord (A1–2) did not affect ulnar MS-induced inhibition of cocaine-induced locomotion (STT X + MS; n = 8) when compared to the control group (STT X; n = 7) or ulnar stimulation without STT lesion (Sham + MS; n = 6; A3). *p < 0.05 vs. STT X. Representative images of STT lesions stained by toluidine blue (A2). (B) Bilateral chemical lesions of the VPL (B1–2) block the inhibitory effects of cocaine locomotion by ulnar MS (VPL X + MS; n = 7), compared to the control groups of VPL X (n = 7) and Sham + MS (n = 6; B3). *p < 0.05 vs. Sham + MS or VPL X + MS.