Silastic silicone tubing

Animals were anesthetized with a mixture of ketamine (87.5 mg/kg, i.p.) and xylazine (5 mg/kg, i.p.) and a catheter (SILASTIC silicone tubing, ID 0.51 mm, OD 0.94 mm, Dow Corning, Midland, MI, USA) inserted into the right jugular vein. The other end of the catheter was inserted subcutaneously through the shoulder blades and exited the skin through a small dermal hole. The catheter was then attached to a guide cannula that was secured with a backpack (Instech, Plymouth Meeting, PA, USA). Rats received ketorolac (3 mg/kg, i.p.) for three days and cefazolin (100 mg/mL, i.v.) for seven days following surgery and received 0.2 ml of heparinized saline (100 U/mL, i.v.) before and after each self-administration session to maintain the patency of the catheter. Catheter patency was verified periodically via methohexital sodium (10 mg/ml; Eli Lilly, Indianapolis, IN, USA). Rats were allowed five days of recovery before starting self-administration of cocaine.

Rats were anesthetized with a mixture of ketamine (100 mg/kg) and xylazine (6 mg/kg). An indwelling catheter (Silastic silicone tubing, Dow Corning, ID 0.63 mm, OD 1.17 mm) was implanted into the right jugular vein as previously described (Covington and Miczek, 2001 (link)). Following 5 days of recovery, rats were placed in a different custom-built chamber (30 × 30.5 × 24.5 cm) within a sound- and light-attenuating enclosure.