ORAL SELF-ADMINISTRATION OF SWEETENED NICOTINE SOLUTIONS BY RATS

Oral self-administration of sweetened nicotine solutions in rats was s tudied in two ways. In the first experiment, one group had continuous access to a water bottle containing a sucrose solution and nicotine (1 0 mu g/ml), while another group had access to an identical sucrose sol ution without nicotine. All rats had continuous access to water. While consumption of nicotine increased with increasing concentrations of s ucrose, consumption of the sucrose + nicotine solution never exceeded the intake of sucrose alone. In subsequent experiments, the delivery o f the solutions was made contingent upon an operant response. The sucr ose + nicotine solution was found to maintain responding to higher res ponse / reinforcer ratios than the sucrose only solution. These data d emonstrate that rats will self-administer sweetened nicotine solutions and that sucrose + nicotine solutions are more reinforcing than sucro se solutions alone. Free accessconsumption is not a good predictor of the response maintaining properties of nicotine solutions.