Intra-nucleus-accumbens SKF38393 improved the impaired acquisition of morphine-conditioned place preference in depression-like rats.
Dopaminergic activity in the nucleus accumbens (NAc) and the globus pallidus (GP) is important for the interaction between depression and addiction, with D1- and D2-like receptors playing different roles. Here, we address the effect of depression on morphine reward and its underlying D1- and D2-like effects in the NAc and/or the GP. Novelty-seeking behaviors and the forced open-space swimming test were used to assess a depression-like state in rats that had undergone chronic mild restraint. Depression-like rats were then trained with morphine-induced conditioned place preference (CPP, 3 mg/kg, 4 days), and showed impaired acquisition of the CPP compared with controls. To examine the receptor-specific dopaminergic mechanism underlying this phenomenon, we microinjected the D1-like agonist SKF38393 (1 μg/side) or the D2-like agonist quinpirole (1 μg/side) into the NAc or the GP. The impairment in acquisition of CPP was reversed only by injecting the D1- but not the D2-like agonist in the NAc. These results suggest that enhancement of dopaminergic transmission in the NAc (via D1-like receptors) may be effective in recovering impaired reward learning during a depression-like state.
Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.|Graduate University of Chinese Academy of Sciences, Beijing, China.
Jun
J
Gao
Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
Ning
N
Zhu
Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.|Graduate University of Chinese Academy of Sciences, Beijing, China.
Min
M
Feng
Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.|Graduate University of Chinese Academy of Sciences, Beijing, China.
Xiaolu
X
Meng
Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
Nan
N
Sui
SKF38393; conditioned place preference; depression-like; morphine; nucleus accumbens