Nicotine maintains robust self-administration in rats on a limited-access schedule

Abstract

Intravenous nicotine maintained substantial responding on the drug-reinforced lever with a limited-access, fixed-ratio 5 schedule of self-administration. Responding demonstrated the expected pharmacological sensitivity; it was dose-dependently reduced by pre-session treatment with either nicotine or mecamylamine but not with hexamethonium. In addition, responding was dependent on the size of the unit dose, with maximum values occurring at 0.01 and 0.03 mg/kg/infusion. Self-administration behavior decreased at doses both above and below these, and extinction followed the substitution of saline for nicotine. Total session drug intake increased with unit dose up to a maximal value of approximately 0.5 mg/kg at 0.03 mg/kg/infusion, but did not increase further at the 0.06 mg/kg/infusion dose. A decrease in the time-out duration at the dose of 0.03 mg/kg/infusion also did not change the total session intake of nicotine. It is suggested that nicotine intake is controlled both by the total amount of drug obtained and by the magnitude of the unit dose. These results demonstrate that intravenous nicotine can maintain substantial self-administration behavior in rodents.

Methylphenidate Enhances the Abuse-Related Behavioral Effects of Nicotine in Rats: Intravenous Self-Administration, Drug Discrimination, and Locomotor Cross-Sensitization

“…One potential interpretation is that methylphenidate attenuated the reinforcing effect of nicotine, thus leading to an increase in nicotine intake in an attempt to surmount the attenuation in reinforcing effectiveness (Yokel, 1987). However, given that prior work has demonstrated that selective nicotinic acetylcholine receptor antagonists such as mecamylamine and dihydro-b-erythriodine generally fail to increase nicotine self-administration (Corrigall and Coen, 1989;Watkins et al, 1999; but see Fattore et al (2002) for evidence of a mecamylamine-induced increase in nicotine self-administration), it seems unlikely that methylphenidate attenuated the reinforcing effect of nicotine. Although an FR schedule was used in the present study, assessing the effects of methylphenidate pretreatment on nicotine selfadministration under a PR schedule could help to clarify the mechanisms underlying the rate-increasing effect of methylphenidate on nicotine self-administration observed using an FR schedule (Arnold and Roberts, 1997;Richardson and Roberts, 1996).…”

“…Nicotine self-administration commenced following a 5-day surgical recovery period, and was based on the general method of Corrigall and Coen (1989), with some modifications. Rats were reintroduced to the operant conditioning chamber during daily 60-min sessions.…”

Nicotine Self-Administration, Extinction Responding and Reinstatement in Adolescent and Adult Male Rats: Evidence Against a Biological Vulnerability to Nicotine Addiction during Adolescence

“…Buprenorphine (0.01 mg/kg, s.c.) was administered as an analgesic and penlong (15 000 (juvenile) or 30 000 U (adult), i.m., Rogar/STP, London, ON, Canada) was used as antibiotic treatment. Juvenile (P26-28) and adult rats (P80-87) were prepared with catheters implanted into the right jugular vein as described previously (Corrigall and Coen, 1989;Le et al, 2006). The catheter exited between the scapulae and was attached to the modified 22-gauge cannula that connected to the fluid swivel system.…”

Discovery of a novel nicotinic receptor antagonist for the treatment of nicotine addiction: 1-(3-Picolinium)-12-triethylammonium-dodecane dibromide (TMPD)

“…An infusion pump was attached to the head mount via a silastic leash during the self-administration sessions. The nicotine self-administration procedure was similar to that described previously [74]. Following recovery from catheter surgery (7 days), rats were reintroduced to operant conditioning chambers for 60-min daily sessions; food restriction was maintained for the duration of the experiment (17−20 g/day, given in the home cage after the session).…”

“…Responses made on one lever (active) were recorded and were followed by an infusion of nicotine (0.03 mg/kg/infusion, 100 μl delivered over 5.9 sec), whereas responses made on the other lever (inactive) were recorded, but had no scheduled consequence. The unit dose of nicotine (0.03 mg/kg/infusion) was chosen based on previously published work [74]. Nicotine was administered i.v.…”