title: Development of an oral operant nicotine/ethanol co-use model in alcohol-preferring (p) rats.
abstract: BACKGROUND
  Alcohol abuse is frequently associated with nicotine (Nic) use. The current experiments were conducted to establish an oral operant ethanol + Nic (EtOH + Nic) co-use model and to characterize some aspects of EtOH + Nic co-use.
  
  
  METHODS
  Rats were allowed to choose between EtOH alone or EtOH + Nic solutions. Additionally, alcohol-preferring (P) rats were allowed to concurrently self-administer 3 distinct EtOH solutions (10, 20, and 30%) with varying amounts of Nic (0.07, 0.14, or 0.21 mg/ml) under operant conditions. P rats were also allowed to concurrently self-administer 2 distinct amounts of Nic (0.07 and 0.14 mg/ml) added to saccharin (Sacc; 0.025%) solutions.
  
  
  RESULTS
  During acquisition, P rats responded for the EtOH + Nic solutions at the same level as for EtOH alone, and responding for EtOH + Nic solutions was present throughout all drinking conditions. P rats also readily maintained stable self-administration behaviors for Nic + Sacc solutions. The results demonstrated that P rats readily acquired and maintained stable self-administration behaviors for EtOH + 0.07 and EtOH + 0.14 mg/ml Nic solutions. Self-administration of EtOH + 0.21 mg/ml Nic was established in only 50% of the subjects. P rats readily expressed seeking behaviors for the EtOH + Nic solutions and reacquired EtOH + Nic self-administration during relapse testing. In addition, tail blood samples indicated that EtOH + Nic co-use resulted in pharmacologically relevant levels of both EtOH and Nic in the blood.
  
  
  CONCLUSIONS
  Overall, the results indicate that P rats readily consume EtOH + Nic solutions concurrently in the presence of EtOH alone, express drug-seeking behaviors, and will concurrently consume physiologically relevant levels of both drugs. These results support the idea that this oral operant EtOH + Nic co-use model would be suitable for studying the development of co-abuse and the consequences of long-term chronic co-abuse.
authors.affiliation: Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA. shhauser@iupui.edu
authors.forename: Sheketha R
authors.initials: SR
authors.lastname: Hauser
authors.forename: Simon N
authors.initials: SN
authors.lastname: Katner
authors.forename: Gerald A
authors.initials: GA
authors.lastname: Deehan
authors.forename: Zheng-Ming
authors.initials: ZM
authors.lastname: Ding
authors.forename: Jamie E
authors.initials: JE
authors.lastname: Toalston
authors.forename: Briana J
authors.initials: BJ
authors.lastname: Scott
authors.forename: Richard L
authors.initials: RL
authors.lastname: Bell
authors.forename: William J
authors.initials: WJ
authors.lastname: McBride
authors.forename: Zachary A
authors.initials: ZA
authors.lastname: Rodd
mesh_terms: D000284:Administration, Oral; D000428:Alcohol Drinking / Q000009:adverse effects / Q000523:psychology; D000818:Animals; D016739:Behavior, Addictive / Q000139:chemically induced* / Q000523:psychology*; D003216:Conditioning, Operant / Q000187:drug effects* / Q000502:physiology; D000431:Ethanol / Q000008:administration & dosage* / Q000633:toxicity; D005260:Female; D023421:Models, Animal; D009538:Nicotine / Q000008:administration & dosage* / Q000633:toxicity; D051381:Rats; D012055:Reinforcement Schedule; D012646:Self Administration; D014029:Tobacco Use Disorder / Q000523:psychology
chemical_list: D000431:Ethanol; D009538:Nicotine