Figure 2.

Substantia nigra infusions of BDNF have no effect on cocaine seeking induced by re-exposure to cocaine cues after 3 and 10 d of withdrawal. A, Mean (±SEM) responses per 2 hr on the previously active lever during the tests for cocaine seeking conducted after 3 and 10 d of withdrawal from cocaine. During the test sessions, cocaine was not available, and lever presses resulted in the delivery of the tone-light cue previously paired with drug infusions. Vehicle or BDNF was infused bilaterally into the SN 1-2 hr after the last training session (n = 7 per group). B, Timeline of the experiment. C, Schematic illustration of the approximate cannula placements within the SN of the 14 rats used in experiment 2. Coronal sections were reproduced from the atlas of Paxinos and Watson (1998), and coordinates are posterior to bregma in millimeters. SA, Self-administration.