Intravenous cocaine, morphine, and amphetamine preferentially increase extracellular dopamine in the ''shell'' as compared with the ''core'' of the rat nucleus accumbens
Intravenous cocaine, morphine, and amphetamine preferentially increase extracellular dopamine in the ''shell'' as compared with the ''core'' of the rat nucleus accumbens
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DOI：
10.1073/pnas.92.26.12304
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发表时间：
1995-12-19
影响因子：
11.1
通讯作者：
DiChiara, G
中科院分区：
文献类型：
--
作者：
Pontieri, FE;Tanda, G;DiChiara, G
伏隔核被认为是滥用药物作用的关键目标。在这个核中，根据解剖学和组织化学标准区分了“壳”和“核”。本研究通过垂直植入同心探针的微透析，研究了自由活动的大鼠静脉注射可卡因、安非他明和吗啡对伏隔核壳和核中细胞外多巴胺浓度的影响。选择的剂量在已知维持大鼠自我给药的剂量范围内，0.2和0.4 mg/kg的吗啡和0.5 mg/kg的可卡因选择性地增加了壳中的细胞外多巴胺。较高剂量的可卡因（1.0 mg/kg）和测试的最低剂量的安非他明（0.125 mg/kg）增加了壳和核心中的细胞外多巴胺，但与核心相比，壳中的效果明显更明显。只有最高剂量的安非他明（0.250 mg/kg）以相似的程度增加壳和核心中的细胞外多巴胺。目前的结果为伏核内的功能区划以及精神兴奋剂和吗啡在已知维持静脉内药物自我给药的剂量下在伏核壳中的优先作用提供了体内神经化学证据。
The nucleus accumbens is considered a critical target of the action of drugs of abuse. In this nucleus a ''shell'' and a ''core'' have been distinguished on the basis of anatomical and histochemical criteria, The present study investigated the effect in freely moving rats of intravenous cocaine, amphetamine, and morphine on extracellular dopamine concentrations in the nucleus accumbens shell and core by means of microdialysis with vertically implanted concentric probes. Doses selected were in the range of those known to sustain drug self-administration in rats, Morphine, at 0.2 and 0.4 mg/kg, and cocaine, at 0.5 mg/kg, increased extracellular dopamine selectively in the shell, Higher doses of cocaine (1.0 mg/kg) and the lowest dose of amphetamine tested (0.125 mg/kg) increased extracellular dopamine both in the shell and in the core, but the effect was significantly more pronounced in the shell compared with the core, Only the highest dose of amphetamine (0.250 mg/kg) increased extracellular dopamine in the shell and in the core to a similar extent, The present results provide in vivo neurochemical evidence for a functional compartmentation within the nucleus accumbens and for a preferential effect of psychostimulants and morphine in the shell of the nucleus accumbens at doses known to sustain intravenous drug self-administration.