Effect of 6-OHDA lesions of the dopaminergic mesolimbic system on drug priming induced reinstatement of extinguished morphine CPP in rats

Beijing Da Xue Xue Bao Yi Xue Ban. 2003 Oct;35(5):449-52.

Abstract

Objective: To evaluate the role played by mesolimbic dopaminergic system in the reinstatement of drug-seeking behavior induced by priming injections of morphine.

Methods: After the extinguishment of morphine conditioned place preference (CPP), low-dose catecholaminergic neurotoxin 6-hydroxydopamine (6-OHDA) was bilaterally injected into ventral tegmental area (VTA, 1 g.L-1) and nucleus accumbens (NAc, 5 g.L-1) before being primed with low-dose morphine.

Results: The effects of drug-priming to induce reinstatement of morphine CPP could be completely abolished by 6-OHDA microinjected into VTA to damage the perikaryon of dopaminergic neurons, or into NAc to lesion the terminal field of the dopaminergic pathway.

Conclusion: The functional integrality of the mesolimbic dopaminergic system is indispensable for drug priming-induced reinstatement of conditioned place preference.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Conditioning, Operant
  • Dopamine
  • Drug-Seeking Behavior*
  • Morphine*
  • Nucleus Accumbens
  • Oxidopamine*
  • Rats

Substances

  • Morphine
  • Oxidopamine
  • Dopamine