Thalamic and hippocampal mechanisms in spatial navigation: A dissociation between brain mechanisms for learning how versus learning where to navigate
Thalamic and hippocampal mechanisms in spatial navigation: A dissociation between brain mechanisms for learning how versus learning where to navigate
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DOI：
10.1016/j.bbr.2006.02.023
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发表时间：
2006-06-30
影响因子：
2.7
通讯作者：
Corcoran, Michael E.
中科院分区：
文献类型：
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作者：
Cain, Donald P.;Boon, Francis;Corcoran, Michael E.
对海马和内侧丘脑（MT）的各种研究表明，这些脑区在空间导航中起着至关重要的、边缘的或不重要的作用。这些不同的观点进行了检查，在实验中使用电解损伤的海马伞穹窿（FF）或射频或神经毒性损伤的MT大鼠随后训练，以找到一个稳定的可见（实验1）或隐藏的平台（实验2和3）在水迷宫（WM）池。电解损伤FF或放射性损伤MT的大鼠在游泳至稳定可见平台时受损，尤其是MT损伤组，表明WM策略获得受损。然后在WM任务的隐藏平台版本中测试额外的损伤大鼠。一些大鼠在损伤前接受Morris的非空间预训练，为它们提供所需的WM行为策略的训练。非空间预训练的大鼠FF病变最终能够导航到隐藏的平台，但位置反应的准确性受损。这种损害发生在没有问题的运动控制游泳或使用WM行为策略，这表明这些大鼠有空间映射障碍。在整个3天的训练中，快频MT损伤阻断了幼稚大鼠对WM行为策略的获取，严重损害了隐藏平台任务各个方面的表现。给予相同MT病变的非空间预训练大鼠很容易学习隐藏的平台位置，并且在整个空间训练中与对照组无法区分。给予MT神经毒性损伤以去除细胞的大鼠仅轻度受损，并且在训练过程中得到相当大的改善，这表明通道纤维在WM策略学习中起重要作用。结果提供了一个明确的分离的作用，MT在学习WM行为策略和海马结构的空间映射和记忆。这是第一次确定的大脑区域，MT，这是必不可少的学习行为策略，本身也不构成任务的解决方案，但必须成功地使用先天的学习能力：使用空间映射的位置反应学习。(c)2006 Elsevier B.V.保留所有权利。
Various studies of hippocampus and medial thalamus (MT) suggest that these brain areas play a crucial, marginal, or no essential role in spatial navigation. These divergent views were examined in experiments using electrolytic Lesions of fimbria-fornix (FF) or radiofrequency or neurotoxic Lesions of MT of rats subsequently trained to find a stable visible (experiment 1) or hidden platform (experiments 2 and 3) in a water maze (WM) pool. Rats with electrolytic Lesions of FF or radiofirequency Lesions of MT were impaired in swimming to a stable visible platform, particularly the MT Lesion Group, suggesting impairment of WM strategies acquisition. Additional Lesioned rats were then tested in a hidden platform version of the WM task. Some rats were given Morris's nonspatial pretraining prior to Lesioning to provide them with training in the required WM behavioral strategies. Nonspatially Pretrained rats with FF Lesions eventually were able to navigate to the hidden platform, but the accuracy of place responding was impaired. This impairment occurred without problems in the motoric control of swimming or the use of WM behavioral strategies, suggesting that these rats had a spatial mapping impairment. Rachofrequency MT Lesions blocked acquisition of WM behavioral strategies by Naive rats throughout 3 days of training, severely impairing performance on all aspects of the hidden platform task. Nonspatially Pretrained rats given the same MT Lesions readily learned the hidden platform location and were indistinguishable from controls throughout spatial training. Rats given neurotoxic Lesions of MT for removal of cells were only mildly impaired and improved considerably during training, suggesting an important role for fibers of passage in WM strategies learning. The results provide a clear dissociation between a role for MT in learning WM behavioral strategies and the hippocampal formation in spatial mapping and memory. This is the first identification of a brain area, MT, that is essential for learning behavioral strategies that by themselves do nor constitute the solution to the task but are necessary for the successful use of an innate learning ability: place response learning using spatial mapping. (c) 2006 Elsevier B.V. All rights reserved.