Fetissov S O, Meguid M M, Chen C, Miyata G
Neuroscience Program, Surgical Metabolism and Nutrition Laboratory, Department of Surgery, SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, USA.
Neuroscience. 2000;101(3):657-63. doi: 10.1016/s0306-4522(00)00374-2.
A positive linear correlation between dopamine and serotonin release was found in the ventromedial hypothalamus and in the lateral hypothalamic area in fasting rats and in fed rats during intermeal intervals. Dopamine release in the ventromedial hypothalamus positively correlated with dopamine and serotonin release in the lateral hypothalamic area, which occurred only during intermeal intervals and was non-significant during the meal consumption periods or during fasting. Meal size correlated significantly only with a decrease in serotonin release in the lateral hypothalamic area. The study was designed to evaluate the relationship between dopamine and serotonin release in these hypothalamic areas and their dependence on feeding status. Microdialysis was performed simultaneously via two probes, one in the ventromedial hypothalamus and the other in the contralateral lateral hypothalamic area, of freely moving male lean Zucker rats over 24h with preserved light and dark phase, either with ad libitum access to food and water, or when no food was available. Dopamine and serotonin concentrations were measured by high-performance liquid chromatography with electrochemical detection in 20-min dialysis samples. Time-series analysis was applied to determine linear correlations between monoamines and in relation to food intake. Data showed that release of dopamine and serotonin is synchronized within the ventromedial hypothalamus and lateral hypothalamic area, particularly in the dark phase and when no food was ingested. However, synchronized release of monoamines between these nuclei occurred only during intermeal intervals: the periods of satiety. These findings suggest a tight relationship between dopaminergic and serotonergic systems of the lateral hypothalamic area and ventromedial hypothalamus, which is influenced by the feeding state and which may be involved in maintaining the balance within and between the centers of the parasympathetic and sympathetic nervous systems. The data also illustate that food intake is coupled unequivocally to the release of dopamine and serotonin in the hypothalamus, suggesting it as a mechanism of activation of postsynaptic neurons associated with new metabolic status.
在禁食大鼠以及进食大鼠餐间间隔期的腹内侧下丘脑和外侧下丘脑区域，发现多巴胺和5-羟色胺释放之间存在正线性相关。腹内侧下丘脑的多巴胺释放与外侧下丘脑区域的多巴胺和5-羟色胺释放呈正相关，这种情况仅在餐间间隔期出现，而在进食期间或禁食期间无显著相关性。进食量仅与外侧下丘脑区域5-羟色胺释放的减少显著相关。本研究旨在评估这些下丘脑区域中多巴胺和5-羟色胺释放之间的关系及其对进食状态的依赖性。通过两根探针同时进行微透析，一根置于自由活动的雄性瘦型 Zucker 大鼠的腹内侧下丘脑，另一根置于对侧外侧下丘脑区域，在保持明暗周期的 24 小时内，大鼠可自由获取食物和水，或者处于无食物供应状态。通过高效液相色谱-电化学检测法测定 20 分钟透析样本中的多巴胺和5-羟色胺浓度。应用时间序列分析来确定单胺之间以及与食物摄入相关的线性相关性。数据显示，多巴胺和5-羟色胺的释放在腹内侧下丘脑和外侧下丘脑区域内是同步的，尤其是在黑暗阶段以及未摄入食物时。然而，这些核团之间单胺的同步释放仅发生在餐间间隔期，即饱腹感期间。这些发现表明，外侧下丘脑区域和腹内侧下丘脑的多巴胺能和5-羟色胺能系统之间存在紧密关系，这种关系受进食状态影响，可能参与维持副交感神经系统和交感神经系统中枢内部以及之间的平衡。数据还表明，食物摄入与下丘脑中多巴胺和5-羟色胺的释放明确相关，提示这是一种与新代谢状态相关的突触后神经元激活机制。
