title: Pharmacological Manipulation of the Rostromedial Tegmental Nucleus Changes Voluntary and Operant Ethanol Self-Administration in Rats.
abstract: BACKGROUND
  The aversive properties of ethanol (EtOH) that limit its intake are poorly understood. There is an increasing interest in the role of the rostromedial tegmental nucleus (RMTg), because it encodes aversion signals and inhibits motivated behaviors. It is also a major source of inhibitory GABAergic inputs to the midbrain dopamine neurons. Up to this time, the role of the RMTg in EtOH-drinking behaviors has not been well explored.
  
  
  METHODS
  Male Long-Evans rats were trained either to drink EtOH under the intermittent 2-bottle-choice protocol or to self-administer EtOH in operant chambers under fixed-ratio-3 schedules. Changes in drinking behaviors induced by the bilateral infusion into the RMTg of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), an agonist of AMPA-type glutamate receptors, or muscimol, an agonist of GABAA receptors, were measured.
  
  
  RESULTS
  Consumption and preference for EtOH, numbers of active lever pressing, and head entrance to the EtOH port were all significantly decreased upon activation of the RMTg by the infusion of AMPA, but were increased upon inhibition of the RMTg by the infusion of muscimol. By contrast, intra-RMTg infusion of these agents did not change sucrose consumption.
  
  
  CONCLUSIONS
  These data show for the first time that EtOH-drinking and EtOH-seeking behaviors of rats changed inversely with RMTg function, supporting the idea that the RMTg plays a crucial role in EtOH-drinking behaviors.
authors.affiliation: Department of Anesthesiology, Pharmacology and Physiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey.
authors.forename: Rao
authors.initials: R
authors.lastname: Fu
authors.affiliation: Department of Anesthesiology, Pharmacology and Physiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey.
authors.forename: Wanhong
authors.initials: W
authors.lastname: Zuo
authors.affiliation: Department of Anesthesiology, Pharmacology and Physiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey.
authors.forename: Danielle
authors.initials: D
authors.lastname: Gregor
authors.affiliation: Department of Anesthesiology, Pharmacology and Physiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Anesthesiology, Pharmacology and Physiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey.
authors.forename: Dennis
authors.initials: D
authors.lastname: Grech
authors.affiliation: Department of Anesthesiology, Pharmacology and Physiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey.
authors.forename: Jiang-Hong
authors.initials: JH
authors.lastname: Ye
mesh_terms: D000428:Alcohol Drinking / Q000188:drug therapy / Q000523:psychology*; D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects* / Q000502:physiology*; D000431:Ethanol / Q000008:administration & dosage*; D008297:Male; D008845:Microinjections; D009118:Muscimol / Q000008:administration & dosage; D045042:Pedunculopontine Tegmental Nucleus / Q000187:drug effects* / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D012646:Self Administration; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000008:administration & dosage
chemical_list: D009118:Muscimol; D000431:Ethanol; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
keywords: Microinjection; Muscimol; Stereotaxic Surgery; α-Amino-3-Hydroxy-5-Methyl-4-Isoxazolepropionic Acid