Voluntary ethanol intake increases extracellular acetylcholine levels in the ventral tegmental area in the rat
Voluntary ethanol intake increases extracellular acetylcholine levels in the ventral tegmental area in the rat
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DOI：
10.1093/alcalc/agh180
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发表时间：
2005-09-01
影响因子：
2.8
通讯作者：
Engel, JA
中科院分区：
文献类型：
--
作者：
Larsson, A;Edström, L;Engel, JA
目的：同时使用乙醇和尼古丁（烟草）是常见的人类。在以前的动物实验中，我们已经证明，烟碱型乙酰胆碱受体，特别是α-芋螺毒素MII和美加明敏感受体位于腹侧被盖区可能参与刺激，多巴胺增强，和奖励乙醇在啮齿动物的影响。乙醇可能通过与烟碱型乙酰胆碱受体直接相互作用和/或通过增强腹侧被盖区细胞外乙酰胆碱水平间接发挥这些作用。本实验研究了乙醇在刺激中脑多巴胺系统中可能的间接作用。研究方法：自愿乙醇摄入对细胞外腹侧被盖乙酰胆碱和多巴胺水平的神经化学作用，通过在体微透析与自由活动的大鼠的双探针方法进行了测量。结果如下：所获得的数据表明，自愿乙醇摄入量（类似于0.7克/千克/小时）导致腹侧被盖区的细胞外乙酰胆碱水平的增加，和几乎时间锁定的多巴胺水平的增加在延髓核。腹侧被盖乙酰胆碱水平和乙醇摄入量以及偏好之间呈正相关。结论：目前的研究结果表明，自愿乙醇摄入量提高细胞外腹侧被盖乙酰胆碱，可能与烟碱乙酰胆碱受体，可能α-芋螺毒素MII敏感受体，定位在腹侧被盖区，随后可能刺激多巴胺溢出的神经核。
Aims: Concurrent use of ethanol and nicotine (tobacco) is often seen in human beings. In previous animal experiments, we have demonstrated that nicotinic acetylcholine receptors, especially alpha-conotoxin MII and mecamylamine sensitive receptors located in the ventral tegmental area may be involved in the stimulatory, dopamine enhancing, and rewarding effects of ethanol in rodents. Ethanol may exert these effects via direct interaction with nicotinic acetylcholine receptors and/or indirectly via enhancement of extracellular acetylcholine levels in the ventral tegmental area. The present experiments investigated a possible indirect effect of ethanol in stimulating the mesoaccumbal dopamine system. Methods: Neurochemical effects of voluntary ethanol intake on extracellular ventral tegmental acetylcholine and accumbal dopamine levels were measured by means of in vivo microdialysis with a two-probe approach in freely moving rats. Results: Obtained data indicate that voluntary ethanol intake (similar to 0.7 g/kg/h) leads to an increase of extracellular acetylcholine levels in the ventral tegmental area, and an almost time-locked increase of dopamine levels in the nucleus accumbens. A positive correlation between the ventral tegmental acetylcholine levels and ethanol intake as well as preference was also observed. Conclusion: The present results suggest that voluntary ethanol intake enhances extracellular ventral tegmental acetylcholine that may interact with nicotinic acetylcholine receptors, possibly alpha-conotoxin MII sensitive receptors, localized in the ventral tegmental area that subsequently may stimulate dopamine overflow in the nucleus accumbens.