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


CONCLUSIONS
The functional integrality of the mesolimbic dopaminergic system is indispensable for drug priming-induced reinstatement of conditioned place preference.
Neuroscience Research Institute, Department of Neurobiology, Peking University, Beijing 100083, China.
Bin
B
Wang
Fei
F
Luo
Xuecai
X
Ge
Aihua
A
Fu
Jisheng
J
Han
D000818:Animals; D003216:Conditioning, Operant; D004298:Dopamine; D058999:Drug-Seeking Behavior; D009020:Morphine; D009714:Nucleus Accumbens; D016627:Oxidopamine; D051381:Rats
D009020:Morphine; D016627:Oxidopamine; D004298:Dopamine