The dual orexin receptor antagonist TCS1102 does not affect reinstatement of nicotine-seeking

PLoS One. 2017 Mar 15;12(3):e0173967. doi: 10.1371/journal.pone.0173967. eCollection 2017.

Abstract

The orexin/hypocretin system is important for appetitive motivation towards multiple drugs of abuse, including nicotine. Both OX1 and OX2 receptors individually have been shown to influence nicotine self-administration and reinstatement. Due to the increasing clinical use of dual orexin receptor antagonists in the treatment of disorders such as insomnia, we examined whether a dual orexin receptor antagonist may also be effective in reducing nicotine seeking. We tested the effect of intracerebroventricular (i.c.v.) administration of the potent and selective dual orexin receptor antagonist TCS1102 on orexin-A-induced food self-administration, nicotine self-administration and reinstatement of nicotine-seeking in rats. Our results show that 30 μg of TCS1102 i.c.v. abolishes orexin-A-induced increases in food self-administration but does not reduce nicotine self-administration. Neither i.c.v. 10 μg nor 30 μg of TCS1102 reduced compound reinstatement after short-term (15 days) self-administration nicotine, but 30 μg transiently reduced cue/nicotine compound reinstatement after chronic self-administration (29 days). These results indicate that TCS1102 has no substantial effect on motivation for nicotine seeking following chronic self-administration and no effect after shorter periods of intake. Orexin receptor antagonists may therefore have little clinical utility against nicotine addiction.

MeSH terms

  • Animals
  • Benzimidazoles / administration & dosage
  • Benzimidazoles / pharmacology*
  • Drug-Seeking Behavior / drug effects*
  • Injections, Intraventricular
  • Nicotine / administration & dosage*
  • Orexin Receptor Antagonists / administration & dosage
  • Orexin Receptor Antagonists / pharmacology*
  • Pyrrolidines / administration & dosage
  • Pyrrolidines / pharmacology*
  • Rats

Substances

  • Benzimidazoles
  • Orexin Receptor Antagonists
  • Pyrrolidines
  • TCS 1102
  • Nicotine

Grants and funding

This work was supported by the National Health & Medical Research Council of Australia (project grant 1047899) and a Future Fellowship to GPM (FT120100250) from the Australian Research Council. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.