The role of alpha6-containing nicotinic acetylcholine receptors in nicotine reward and withdrawal

J Pharmacol Exp Ther. 2009 Nov;331(2):547-54. doi: 10.1124/jpet.109.155457. Epub 2009 Jul 30.

Abstract

The alpha6 nicotinic acetylcholine receptor (nAChR) subunit is involved in nicotine-stimulated dopamine release in the striatum. It is expressed in brain regions and coexpressed with nAChR subtypes implicated in nicotine dependence behaviors; hence, this subunit may play a role in nicotine dependence. Using the alpha6-selective antagonist alpha-conotoxin H9A;L15A (MII[H9A;L15A]), we determined the role of alpha6* nAChRs in the pharmacological and behavioral effects of nicotine. We measured effects of pretreatment with MII[H9A;L15A] on analgesia, locomotion, and body temperature after a single injection of nicotine. Effects of MII[H9A;L15A] on nicotine reward were measured using the conditioned place preference (CPP) paradigm. We further measured physical (somatic signs and hyperalgesia) and affective [anxiety-related behavior and conditioned place aversion (CPA)] nicotine withdrawal behaviors after extended nicotine exposure. Results showed that MII[H9A;L15A] did not block acute nicotine effects on the behaviors measured. Conversely, MII[H9A:l15A] blocked the expression of nicotine CPP, as well as withdrawal-associated CPA and anxiety-related behavior in the elevated plus maze, but not withdrawal-induced somatic signs or hyperalgesia. These results suggest a role for the alpha6 nAChR subunit in nicotine reward and affective nicotine withdrawal but not acute nicotine-induced or physical withdrawal behaviors.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Anxiety / psychology
  • Avoidance Learning / drug effects
  • Body Temperature / drug effects
  • Calcium Channel Blockers / pharmacology
  • Conditioning, Operant / drug effects
  • Conotoxins / pharmacology
  • Dose-Response Relationship, Drug
  • Injections, Intraventricular
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Motor Activity / drug effects
  • Nicotine / adverse effects
  • Nicotine / pharmacology*
  • Nicotinic Agonists / adverse effects
  • Nicotinic Agonists / pharmacology*
  • Nicotinic Antagonists / pharmacology
  • Pain Measurement / drug effects
  • Reaction Time / drug effects
  • Receptors, Nicotinic / drug effects*
  • Reward*
  • Substance Withdrawal Syndrome / physiopathology*
  • Substance Withdrawal Syndrome / psychology

Substances

  • Calcium Channel Blockers
  • Conotoxins
  • Nicotinic Agonists
  • Nicotinic Antagonists
  • Receptors, Nicotinic
  • nicotinic receptor alpha6
  • Nicotine