title: The posterior ventral tegmental area mediates alcohol-seeking behavior in alcohol-preferring rats.
abstract: The mesolimbic dopamine (DA) system is involved in the rewarding process of drugs of abuse and is activated during the anticipation of drug availability. However, the neurocircuitry that regulates ethanol (EtOH)-seeking has not been adequately investigated. The objectives of the present study were to determine 1) whether the posterior ventral tegmental area (p-VTA) mediates EtOH-seeking, 2) whether microinjections of EtOH into the p-VTA could stimulate EtOH-seeking, and (3) the involvement of p-VTA DA neurons in EtOH-seeking. Alcohol-preferring rats were trained to self-administer 15% EtOH and water. After 10 weeks, rats underwent extinction training, followed by 2 weeks in their home cages. During the home-cage period, rats were then bilaterally implanted with guide cannulae aimed at the p-VTA or anterior ventral tegmental area (a-VTA). EtOH-seeking was assessed by the Pavlovian spontaneous recovery model. Separate experiments examined the effects of: 1) microinjection of quinpirole into the p-VTA, 2) EtOH microinjected into the p-VTA, 3) coadministration of EtOH and quinpirole into the p-VTA, 4) microinjection of quinpirole into the a-VTA, and 5) microinjection of EtOH into the a-VTA. Quinpirole microinjected into the p-VTA reduced EtOH-seeking. Microinjections of EtOH into the p-VTA increased EtOH-seeking. Pretreatment with both quinpirole and EtOH into the p-VTA reduced EtOH-seeking. Microinjections of quinpirole or EtOH into the a-VTA did not alter EtOH-seeking. Overall, the results suggest that the p-VTA is a neuroanatomical substrate mediating alcohol-seeking behavior and that activation of local DA neurons is involved.
authors.affiliation: Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA. shhauser@iupui.edu
authors.forename: Sheketha R
authors.initials: SR
authors.lastname: Hauser
authors.forename: Zheng-Ming
authors.initials: ZM
authors.lastname: Ding
authors.forename: Bruk
authors.initials: B
authors.lastname: Getachew
authors.forename: Jamie E
authors.initials: JE
authors.lastname: Toalston
authors.forename: Scott M
authors.initials: SM
authors.lastname: Oster
authors.forename: William J
authors.initials: WJ
authors.lastname: McBride
authors.forename: Zachary A
authors.initials: ZA
authors.lastname: Rodd
mesh_terms: D000428:Alcohol Drinking / Q000235:genetics* / Q000503:physiopathology / Q000523:psychology*; D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects / Q000502:physiology; D000431:Ethanol / Q000008:administration & dosage; D005260:Female; D008845:Microinjections; D019257:Quinpirole / Q000008:administration & dosage; D051381:Rats; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D012646:Self Administration; D017557:Ventral Tegmental Area / Q000187:drug effects / Q000502:physiology*
chemical_list: D019257:Quinpirole; D000431:Ethanol