Goodman Jarid, Packard Mark G
Department of Psychology, Texas A&M Institute for Neuroscience, Texas A&M University College Station, TX, USA.
Front Behav Neurosci. 2015 Nov 24;9:314. doi: 10.3389/fnbeh.2015.00314. eCollection 2015.
Previous research indicates that extinction of rodent maze behavior may occur without explicit performance of the previously acquired response. In latent extinction, confining an animal to a previously rewarded goal location without reinforcement is typically sufficient to produce extinction of maze learning. However, previous studies have not determined whether latent extinction may be successfully employed to extinguish all types of memory acquired in the maze, or whether only specific types of memory may be vulnerable to latent extinction. The present study examined whether latent extinction may be effective across two plus-maze tasks that depend on anatomically distinct neural systems. Adult male Long-Evans rats were trained in a hippocampus-dependent place learning task (Experiment 1), in which animals were trained to approach a consistent spatial location for food reward. A separate group of rats were trained in a dorsolateral striatum-dependent response learning task (Experiment 2), in which animals were trained to make a consistent egocentric body-turn response for food reward. Following training, animals received response extinction or latent extinction. For response extinction, animals were given the opportunity to execute the original running approach response toward the empty food cup. For latent extinction, animals were confined to the original goal locations with the empty food cup, thus preventing them from making the original running approach response. Results indicate that, relative to no extinction, latent extinction was effective at extinguishing memory in the place learning task, but remained ineffective in the response learning task. In contrast, typical response extinction remained very effective at extinguishing memory in both place and response learning tasks. The present findings confirm that extinction of maze learning may occur with or without overt performance of the previously acquired response, but that the effectiveness of latent extinction may depend on the type of memory being extinguished. The findings suggest that behavioral treatments modeled after response extinction protocols may be especially useful in alleviating human psychopathologies involving striatum-dependent memory processes (e.g., drug addiction and relapse).
先前的研究表明，啮齿动物迷宫行为的消退可能在没有明确表现出先前习得反应的情况下发生。在潜伏消退中，将动物限制在先前有奖励的目标位置而不给予强化通常足以导致迷宫学习的消退。然而，先前的研究尚未确定潜伏消退是否可以成功用于消除在迷宫中获得的所有类型的记忆，或者是否只有特定类型的记忆可能易受潜伏消退的影响。本研究考察了潜伏消退在依赖解剖学上不同神经系统的两个十字迷宫任务中是否有效。成年雄性长 Evans 大鼠在一项依赖海马体的位置学习任务（实验 1）中接受训练，在该任务中，动物被训练接近一个一致的空间位置以获取食物奖励。另一组大鼠在一项依赖背外侧纹状体的反应学习任务（实验 2）中接受训练，在该任务中，动物被训练做出一致的以自我为中心的身体转动反应以获取食物奖励。训练后，动物接受反应消退或潜伏消退。对于反应消退，给予动物机会对空食物杯执行原来的奔跑接近反应。对于潜伏消退，将动物限制在带有空食物杯的原来目标位置，从而阻止它们做出原来的奔跑接近反应。结果表明，相对于无消退，潜伏消退在位置学习任务中有效消除记忆，但在反应学习任务中仍然无效。相比之下，典型的反应消退在位置和反应学习任务中仍然非常有效地消除记忆。本研究结果证实，迷宫学习的消退可能在有或没有先前习得反应的明显表现的情况下发生，但潜伏消退的有效性可能取决于被消除的记忆类型。研究结果表明，模仿反应消退方案的行为治疗可能在减轻涉及依赖纹状体记忆过程的人类精神病理学（例如药物成瘾和复发）方面特别有用。
