Self administration of nicotine with and without a food delivery schedule

Abstract Rats have been shown to self administer a range of narcotic drugs using self injection procedures. However, studies of self administration of nicotine have been less successful in inducing rates of self injection comparable to that with narcotics. In this study different methods of self administration of nicotine by naive rats are evaluated. In the three series of experiments reported, rats self injected nicotine or saline through the jugular vein under normal body weight and reduced body weight conditions and also when the inhections were adjunctive to a food delivery schedule. In a fourth series of experiments, oral intake of nicotine by rats under the condition of a food delivery schedule was investigated. The ratesof self injection of nicotine by rats over a continuous 90 hr session were similar to saline injection rates. At reduced body weight the rate of self injection of nicotine was greater than saline. On a fixed interval 60 sec food delivery schedule for two hr day, the rate of self injection of nicotine was significantly greater than the rate of self injection of saline under the same conditions and also signigicantly greater than that for nicotine injections at reduced body weight without the schedule. The oral intake of nicotine under the same conditions was similar to the intake of nicotine by schedule induced injections. Schedule induced self-injections provide a paradigm for testing drug and environmental interactions.