When administered into the nucleus accumbens core or shell, the NMDA receptor antagonist AP-5 reinstates cocaine-seeking behavior in the rat

Neurosci Lett. 2007 Jun 13;420(2):169-73. doi: 10.1016/j.neulet.2007.04.063. Epub 2007 May 3.


Nucleus accumbens glutamate transmission plays a critical role in cocaine priming-induced reinstatement of drug seeking. Previous studies have demonstrated that systemic or intra-accumbens shell administration of an NMDA receptor antagonist reinstates cocaine-seeking behavior. However, it is unclear if antagonizing NMDA receptors in the nucleus accumbens core or shell subregions will differentially affect cocaine reinstatement. To investigate this possibility, we microinjected the competitive NMDA receptor antagonist AP-5 (0, 3 or 30 microg) into either the nucleus accumbens core or shell and assessed the reinstatement of cocaine-seeking behavior. When microinjected into the shell, both doses of AP-5 produced reinstatement of cocaine seeking. In contrast, when administered into the core, only the highest dose of AP-5 reinstated cocaine-seeking behavior; moreover, the magnitude of this effect was substantially less than when AP-5 was administered into the shell. This study provides evidence that pharmacological antagonism of NMDA receptors in the nucleus accumbens core or shell promotes the reinstatement of cocaine seeking.

Publication types

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

MeSH terms

  • 2-Amino-5-phosphonovalerate / pharmacology*
  • Animals
  • Cocaine / adverse effects
  • Cocaine / agonists*
  • Cocaine-Related Disorders / metabolism
  • Cocaine-Related Disorders / physiopathology*
  • Dopamine Uptake Inhibitors / adverse effects
  • Dopamine Uptake Inhibitors / agonists
  • Dose-Response Relationship, Drug
  • Excitatory Amino Acid Antagonists / pharmacology
  • Exploratory Behavior / drug effects
  • Exploratory Behavior / physiology
  • Glutamic Acid / metabolism
  • Male
  • Nucleus Accumbens / drug effects*
  • Nucleus Accumbens / metabolism
  • Nucleus Accumbens / physiopathology
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, N-Methyl-D-Aspartate / drug effects*
  • Receptors, N-Methyl-D-Aspartate / metabolism
  • Recurrence


  • Dopamine Uptake Inhibitors
  • Excitatory Amino Acid Antagonists
  • Receptors, N-Methyl-D-Aspartate
  • Glutamic Acid
  • 2-Amino-5-phosphonovalerate
  • Cocaine