Stimulation of 5-HT1B receptors enhances cocaine reinforcement yet reduces cocaine-seeking behavior: PRECLINICAL STUDY

Nathan S. Pentkowski, Jazmin I. Acosta, Jenny R. Browning, Elizabeth C. Hamilton, Janet Neisewander

Research output: Contribution to journalArticle

38 Scopus citations

Abstract

Paradoxically, stimulation of 5-HT1B receptors (5-HT 1BRs) enhances sensitivity to the reinforcing effects of cocaine but attenuates incentive motivation for cocaine as measured using the extinction/reinstatement model. We revisited this issue by examining the effects of a 5-HT1BR agonist, CP94253, on cocaine reinforcement and cocaine-primed reinstatement, predicting that CP94253 would enhance cocaine-seeking behavior reinstated by a low priming dose, similar to its effect on cocaine reinforcement. Rats were trained to self-administer cocaine (0.75 mg/kg, i.v.) paired with light and tone cues. For reinstatement experiments, they then underwent daily extinction training to reduce cocaine-seeking behavior (operant responses without cocaine reinforcement). Next, they were pre-treated with CP94253 (3-10 mg/kg, s.c.) and either tested for cocaine-primed (10 or 2.5 mg/kg, i.p.) or cue-elicited reinstatement of extinguished cocaine-seeking behavior. For reinforcement, effects of CP94253 (5.6 mg/kg) across a range of self-administered cocaine doses (0-1.5 mg/kg, i.v.) were examined. Cocaine dose-dependently reinstated cocaine-seeking behavior, but contrary to our prediction, CP94253 reduced reinstatement with both priming doses. Similarly, CP94253 reduced cue-elicited reinstatement. In contrast, CP94253 shifted the self-administration dose-effect curve leftward, consistent with enhanced cocaine reinforcement. When saline was substituted for cocaine, CP94253 reduced response rates (i.e. cocaine-seeking behavior). In subsequent control experiments, CP94253 decreased open-arm exploration in an elevated plus-maze suggesting an anxiogenic effect, but had no effect on locomotion or sucrose reinforcement. These results provide strong evidence that stimulation of 5-HT1BRs produces opposite effects on cocaine reinforcement and cocaine-seeking behavior, and further suggest that 5-HT1BRs may be a novel target for developing medications for cocaine dependence.

Original languageEnglish (US)
Pages (from-to)419-430
Number of pages12
JournalAddiction Biology
Volume14
Issue number4
DOIs
StatePublished - Oct 1 2009

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Keywords

  • CP94253
  • Extinction
  • Motivation
  • Reinstatement
  • Relapse
  • Sucrose reinforcement

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Pharmacology
  • Psychiatry and Mental health

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