Effects of Nicotine and Ethanol on Indices of Reward and Sensory-Motor Function in Rats: Implications for the Positive Epidemiologic Relationship Between the Use of Cigarettes and the Use of Alcohol
Abstract
The present experiments examined effects of nicotine and ethanol on behavioral and biochemical indices of reward and sensory-motor function in rats. In Experiment 1, the conditioned place preference paradigm was used to assess nicotine reward following acute treatment with ethanol or saline. Contrary to predictions, there was no evidence of place conditioning by nicotine and no effects of ethanol to alter nicotine place preference. There was, however, an effect of nicotine to offset the locomotor depressant effects of ethanol as indexed by the number of crosses between two shuttle-box chambers. In addition, there was a significant effect of nicotine and ethanol to reduce the ratio of dopamine/DOPAC in nucleus accumbens. Because dopaminergic activity in nucleus accumbens is known to mediate nicotine reinforcement, reductions in the ratio of dopamine/DOPAC (perhaps indicating an increase in the rate of dopamine turnover) suggest a biologic mechanism that may motivate some smokers to smoke more when they drink. In Experiment 2, the acoustic startle response paradigm was used to assess effects of nicotine and ethanol on behavioral indices of sensory-motor function in rats. Results indicate a significant interaction of nicotine with ethanol to influence the acoustic startle response (ASR) and to influence pre-pulse inhibition of the acoustic startle response (PP!). More specifically, nicotine administration attenuated effects of low-dose ethanol to increase ASR and PPI. These data were interpreted as evidence that nicotine and ethanol can interact to influence sensory-motor function. Because some smokers may smoke to regulate psychomotor function, these results suggest a behavioral mechanism that may motivate some individuals to smoke more when they drink.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1997
- Accession Number
- ADA444389
Entities
People
- Eric J. Popke
Organizations
- Uniformed Services University of the Health Sciences