title: The effects of varenicline on methamphetamine self-administration and drug-primed reinstatement in male rats.
abstract: Methamphetamine (meth) addiction is a costly burden to both the individual user and society as a whole. Establishing effective pharmacotherapies to treat meth dependence is needed to help solve this health problem. The study reported herein examined the effects of varenicline, a partial α4β2 and full α7 nicotinic acetylcholine receptor agonist, on meth self-administration and reinstatement in male Sprague-Dawley rats. Following indwelling jugular catheter surgery, rats were either trained to self-administer meth or saline on a variable ratio (VR) 3 schedule of reinforcement. Self-administration sessions (2h duration; 19 total sessions) were conducted daily. The effect of varenicline pretreatment on meth and saline self-administration was then determined using a within-study design. All rats received varenicline (0.0, 0.3, 1.0, and 3.0mg/kg) prior to 4 different test sessions. Dose order was randomly assigned and each test was separated by 2 standard self-administration sessions to assess stability of responding. Fifteen extinction sessions (no meth available) followed the last test. Extinction was followed by meth-primed (0.3mg/kg IP) reinstatement tests to examine the effect of varenicline on meth-seeking behavior. All rats again received all doses of varenicline over 4 separate reinstatement tests performed on 4 consecutive days. Varenicline did not alter self-administration of meth or saline. Additionally, the 0.3 and 1.0 doses of varenicline non-specifically increased active lever responding during the reinstatement test sessions. This latter finding suggests that varenicline may increase relapse liability and should not be utilized as pharmacotherapy to treat meth dependence.
authors.affiliation: Yale University School of Medicine, Division of Molecular Psychiatry, New Haven, CT, USA. Electronic address: pittenges@gmail.com.
authors.forename: Steven T
authors.initials: ST
authors.lastname: Pittenger
authors.affiliation: University of Nebraska-Lincoln, Department of Psychology, Lincoln, NE, USA.
authors.forename: Scott T
authors.initials: ST
authors.lastname: Barrett
authors.affiliation: University of Nebraska Medical Center School of Medicine Omaha, NE, USA.
authors.forename: Shinnyi
authors.initials: S
authors.lastname: Chou
authors.affiliation: University of Nebraska-Lincoln, Department of Psychology, Lincoln, NE, USA.
authors.forename: Rick A
authors.initials: RA
authors.lastname: Bevins
mesh_terms: D019969:Amphetamine-Related Disorders / Q000188:drug therapy*; D000704:Analysis of Variance; D000818:Animals; D000697:Central Nervous System Stimulants / Q000008:administration & dosage*; D003216:Conditioning, Operant; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D058999:Drug-Seeking Behavior / Q000187:drug effects; D005108:Extinction, Psychological / Q000187:drug effects; D008124:Locomotion / Q000187:drug effects; D008297:Male; D008694:Methamphetamine / Q000008:administration & dosage*; D018722:Nicotinic Agonists / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012201:Reward; D012646:Self Administration; D000068580:Varenicline / Q000627:therapeutic use*
chemical_list: D000697:Central Nervous System Stimulants; D018722:Nicotinic Agonists; D008694:Methamphetamine; D000068580:Varenicline
keywords: Addiction; Chantix; Drug dependence; Relapse; Reward enhancement