Cocaine seeking and taking: role of hippocampal dopamine D1-like receptors

Int J Neuropsychopharmacol. 2014 Sep;17(9):1533-8. doi: 10.1017/S1461145714000340. Epub 2014 Mar 21.

Abstract

Despite the well-documented involvement of dopamine D1-like receptor stimulation in cocaine-induced goal-directed behaviours, little is known about the specific contribution of D1-like receptor populations in the dorsal hippocampus (DH) to drug context-induced cocaine-seeking or drug-reinforced instrumental behaviours. To investigate this question, rats were trained to lever press for un-signalled cocaine infusions in a distinct context followed by extinction training in a different context. Cocaine-seeking behaviour (non-reinforced lever responding) was then assessed in the previously cocaine-paired and extinction contexts. SCH23390-induced D1-like receptor antagonism in the DH, but not the overlying trunk region of the somatosensory cortex, dose-dependently inhibited drug context-induced cocaine-seeking behaviour, without altering cocaine-reinforced instrumental responding, cocaine intake, food-reinforced instrumental responding, or general motor activity, relative to vehicle treatment. These findings suggest that D1-like receptor stimulation in the DH is critical for the incentive motivational effects and/or memory of cocaine-paired contextual stimuli that contribute to drug-seeking behaviour.

Publication types

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

MeSH terms

  • Animals
  • Benzazepines / pharmacology
  • Cocaine / administration & dosage*
  • Conditioning, Operant / drug effects
  • Dopamine Antagonists / pharmacology
  • Dopamine Uptake Inhibitors / administration & dosage*
  • Drug-Seeking Behavior / drug effects*
  • Extinction, Psychological / drug effects
  • Functional Laterality
  • Hippocampus / drug effects
  • Hippocampus / metabolism*
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Dopamine D1 / antagonists & inhibitors
  • Receptors, Dopamine D1 / metabolism*
  • Reinforcement, Psychology
  • Self Administration

Substances

  • Benzazepines
  • Dopamine Antagonists
  • Dopamine Uptake Inhibitors
  • Receptors, Dopamine D1
  • SCH 23390
  • Cocaine