Effects of the opioid antagonist naltrexone on feeding induced by DAMGO in the ventral tegmental area and in the nucleus accumbens shell region in the rat
Effects of the opioid antagonist naltrexone on feeding induced by DAMGO in the ventral tegmental area and in the nucleus accumbens shell region in the rat
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DOI：
10.1152/ajpregu.00271.2003
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发表时间：
2003-11-01
影响因子：
2.8
通讯作者：
Levine, AS
中科院分区：
文献类型：
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作者：
MacDonald, AF;Billington, CJ;Levine, AS
中脑边缘核壳区（nucleus bens shell region，sNAcc）和腹侧被盖区（ventral tegmental area，VTA）是中脑边缘多巴胺通路的两个主要节点，介导包括进食在内的各种生存行为的奖赏。阿片类药物在外周和中枢注射时增加并维持食物摄入。腹侧被盖区中的阿片类物质导致sNAc中多巴胺的释放增加，并且当注射到任一部位时，导致食物摄入量增加。本研究中的动物在VTA和sNAcc中双重插管，并在两个部位注射纳洛酮（NTX）（2.5、5和25 μ g/侧）和Tyr-D-Ala-Gly-（Me）Phe-Gly-ol（DAMGO）（0.1、0.3、1、3和5 nmol/侧）的各种组合。DAMGO被发现剂量依赖性增加摄入量在相同程度上注射到任何一个网站。DAMGO诱导的食物摄入量的增加，当注射到VTA被阻断到控制水平与最高剂量的NTX双侧注射到sNAcc;然而，增加的摄入量时，注射到sNAcc被阻断只有部分由最高剂量的NTX双侧注射到VTA。这些结果表明两个位点之间存在阿片类药物-阿片类药物的交流;然而，这种交流可能是间接的，需要其他位点和递质来引起行为的改变。
The nucleus accumbens shell region (sNAcc) and the ventral tegmental area (VTA) are two major nodes in the mesolimbic dopamine pathway, which mediates reward for various survival behaviors, including feeding. Opioids increase and maintain food intake when injected peripherally and centrally. Opioids in the VTA cause increased release of dopamine in the sNAcc, and when injected into either site, cause an increase in food intake. Animals in this study were double cannulated in the VTA and in the sNAcc and injected with various combinations of naltrexone (NTX) (2.5, 5, and 25 mug/side) and Tyr-D-Ala-Gly-(Me) Phe-Gly-ol( DAMGO) (0.1, 0.3, 1, 3, and 5 nmol/side) in both sites. DAMGO was found to dose dependently increase intake to an equal extent when injected into either site. DAMGO-induced increases in food intake when injected into the VTA were blocked to control levels with the highest dose of NTX injected bilaterally into the sNAcc; however, increases in intake when injected into the sNAcc were blocked only partially by the highest dose of NTX injected bilaterally into the VTA. These results indicate opioid-opioid communication between the two sites; however, the communication may be quite indirect, requiring other sites and transmitters to elicit a change in behavior.