Are all reinforcers the same? A memory consolidation perspective

强化物的“记忆增强”假说产生了三个可测试的预测。首先，不同的强化物应该通过作用于记忆巩固的重叠神经化学系统来强化行为。其次，由于这些神经化学系统重叠，不同强化物之间应该存在行为相互作用。最后，在哺乳动物的大脑中，相互作用的神经化学系统汇聚成记忆巩固的主要“途径”。******为了验证这些预测，Sprague-Dawley大鼠将被训练将特定的动作（在自我管理时按杠杆）或环境刺激（在场所条件反射时的白室）与各种强化物的传递联系起来。在训练之后，在没有强化物的情况下，这些联想的记忆将通过评估学习行为的持久性或接近环境刺激的频率来衡量。******研究1-9将采用药理学和神经生物学方法来研究由糖精、果糖、葡萄糖、羟考酮和可卡因参与的记忆巩固系统。之所以选择这些强化物，是因为尽管它们对身体和大脑的影响不同，但它们都是由老鼠自行施用的。“糖果”将自行口服，药物将静脉注射。在研究10中，大鼠将接受双重自我给药过程的训练，在存在和不存在一种或两种强化物的情况下，行为相互作用将在各种测试中得到表征。最后，研究11-13将采用神经药理学方法探索多巴胺和去甲肾上腺素之间的相互作用；这两个系统很可能与所有强化刺激激活的记忆巩固途径有关。******这个创新的研究项目调查了心理学和神经科学中长期存在的基本问题。不同强化物在记忆巩固过程中所产生的神经和行为效应尚未有系统的探讨。而且，解决各种强化物如何促进学习的问题，不仅是理解行为的核心，而且还与人类健康（例如肥胖和物质依赖）直接相关

The "memory enhancing" hypothesis of reinforcers generates three testable predictions. First, different reinforcers should strengthen behavior through actions on overlapping neurochemical systems of memory consolidation. Second, because these neurochemical systems overlap, there should be behavioural interactions between different reinforcers. Finally, in the mammalian brain, interacting neurochemical systems converge into a primary "pathway" of memory consolidation. ******To test these predictions, Sprague-Dawley rats will be trained to associate particular actions (pressing a lever during self-administration) or environmental stimuli (a white chamber during place conditioning), with the delivery of various reinforcers. Following training, the memories of these associations will be measured by assessing the persistence of the learned actions, or the frequency of approach to the environmental stimuli, in the absence of reinforcers. ******Studies 1-9 will employ pharmacological and neurobiological methods to study systems of memory consolidation engaged by saccharin, fructose, glucose, oxycodone and cocaine. These reinforcers have been selected because, although they have different effects on the body and on the brain, they are all self-administered by rats. The "sweets" will be self-administered intraorally and the drugs intravenously. In Study 10, rats will be trained in a dual self-administration procedure, and behavioural interactions will be characterized during various tests in the presence and absence of one or both reinforcers. Finally, Studies 11-13 will employ neuro-pharmacological methods to explore the interaction between dopamine and noradrenaline; two systems that likely contribute to a pathway of memory consolidation activated by all reinforcing stimuli. ******This innovative program of research investigates long-standing, basic questions in psychology and neuroscience. There have been no systematic explorations of the neural and behavioral effects produced by different reinforcers in the context of memory consolidation. And, addressing the question of how various reinforcers promote learning, is not only central to the understanding of behavior, but it is also of direct relevance to human health (e.g., obesity and substance dependence).**