Naloxone effects on sucrose-motivated behavior
Naloxone effects on sucrose-motivated behavior
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DOI：
10.1007/bf02246345
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发表时间：
1996-07-01
影响因子：
3.4
通讯作者：
Levine, AS
中科院分区：
文献类型：
--
作者：
Cleary, J;Weldon, DT;Levine, AS
阿片系统在喂养中发挥着重要作用。一般来说，阿片类激动剂通常会增加非食物限制动物的摄食，而阿片类拮抗剂则会减少摄食。在饮食受限的动物中，这些药物的作用大大降低。阿片类拮抗剂在减少甜食消费方面显示出显着的功效。对这种强大作用的解释通常集中在药物引起的味道、味觉或适口性的变化上。目前的研究将阿片类拮抗剂纳洛酮对获得不同浓度蔗糖的动机的影响与该药物对不受限制的蔗糖溶液消耗的影响联系起来。根据渐进比例强化计划（PR）评估响应动机的变化，这需要增加每个连续单位的蔗糖溶液的响应成本。通过 PR 测量的动机随着蔗糖浓度的增加而增加，纳洛酮对给定的蔗糖浓度产生反应动机的剂量依赖性下降。因此，纳洛酮的有效性与蔗糖浓度的强度间接相关。在不受限制地获取蔗糖溶液的情况下，纳洛酮在较高浓度下最大程度地减少了消耗。数据表明，纳洛酮对甜味食物的至少部分影响可能是通过反映在动机测量中的内源性阿片类奖励系统介导的。
The opioid system plays an important role in feeding. In general, opioid agonists typically increase feeding and opioid antagonists decrease feeding in nonfood restricted animals. In food restricted animals the effects of these drugs are substantially reduced. Opioid antagonists have shown a marked effectiveness at reducing consumption of sweet foods, Explanations for this robust effect have typically focused on drug induced changes in taste, taste perception, or palatability. The current study relates the effects of the opioid antagonist naloxone on motivation to obtain different sucrose concentrations to the drug's effects on unrestricted sucrose solution consumption. Changes in motivation to respond were assessed under a progressive ratio reinforcement schedule (PR) which required increased response cost for each successive unit of sucrose solution. Motivation, as measured by the PR, increased as sucrose concentration increased and naloxone produced a dose-dependent decrease in motivation to respond for a given sucrose concentration. Thus, the effectiveness of naloxone was indirectly related to strength of the sucrose concentration. Under unrestricted access to sucrose solutions, naloxone reduced consumption greatest under the higher concentrations. The data suggest at least part of naloxone's effects on sweet tasting food may be mediated through endogenous opioid reward systems that are reflected in measures of motivation.