Oxytocin decreases methamphetamine self-administration, methamphetamine hyperactivity, and relapse to methamphetamine-seeking behaviour in rats

Neuropharmacology. 2010 Jan;58(1):38-43. doi: 10.1016/j.neuropharm.2009.06.018. Epub 2009 Jun 26.

Abstract

There is emerging evidence that the neuropeptide oxytocin may be utilised as a treatment for various psychopathologies, including drug addictions. Here we used an animal model to assess whether oxytocin might be effective in the treatment of methamphetamine addiction. Sprague-Dawley rats were trained to lever press to intravenously self-administer methamphetamine under a progressive ratio schedule of reinforcement. Once responding had stabilised, one group of rats received escalating doses of oxytocin (0.001, 0.01, 0.1, 0.3, 1 mg/kg) administered intraperitoneally (IP) prior to daily self-administration tests, while other rats received vehicle. After these tests, lever-pressing was extinguished and the ability of methamphetamine primes (IP, 1 mg/kg) to reinstate responding was studied with and without co-administration of oxytocin (IP, 0.3 and 1 mg/kg). Results showed that oxytocin dose-dependently reduced responding for intravenous methamphetamine with an almost complete absence of responding at the highest oxytocin dose (1 mg/kg). Hyperactivity during methamphetamine self-administration was also dose-dependently reduced by oxytocin. Oxytocin (1 but not 0.3 mg/kg) also reduced the ability of methamphetamine to reinstate methamphetamine-seeking behaviour. In separate tests, oxytocin (IP, 0.3 and 1 mg/kg) robustly decreased the hyperactivity and rearing induced by methamphetamine challenge (IP, 1 mg/kg), producing activity levels similar to control animals. This study suggests that oxytocin may have a powerful inhibitory effect on the motivation to consume methamphetamine and on hyperactivity associated with acute methamphetamine intoxication. These results point to the potential utility of human trials of oxytocin as a therapeutic treatment for methamphetamine addiction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amphetamine-Related Disorders* / drug therapy
  • Amphetamine-Related Disorders* / etiology
  • Amphetamine-Related Disorders* / psychology
  • Analysis of Variance
  • Animals
  • Behavior, Animal / drug effects
  • Central Nervous System Stimulants / administration & dosage*
  • Central Nervous System Stimulants / adverse effects
  • Central Nervous System Stimulants / pharmacology
  • Conditioning, Operant / drug effects
  • Conditioning, Operant / physiology
  • Dose-Response Relationship, Drug
  • Male
  • Methamphetamine / administration & dosage*
  • Methamphetamine / adverse effects
  • Methamphetamine / pharmacology
  • Motor Activity / drug effects
  • Oxytocics / therapeutic use*
  • Oxytocin / therapeutic use*
  • Rats
  • Rats, Sprague-Dawley
  • Reinforcement Schedule
  • Self Administration

Substances

  • Central Nervous System Stimulants
  • Oxytocics
  • Methamphetamine
  • Oxytocin