Dissociable memory effects after medial thalamus lesions in the rat
Dissociable memory effects after medial thalamus lesions in the rat
复制标题
DOI：
10.1111/j.1460-9568.2005.04199.x
复制
发表时间：
2005-08-01
影响因子：
3.4
通讯作者：
Dalrymple-Alford, JC
中科院分区：
文献类型：
--
作者：
Mitchell, AS;Dalrymple-Alford, JC
间脑性遗忘症病例中的神经病理学变化导致在识别关键丘脑核团及其在学习和记忆中的潜在作用方面存在不确定性。基于内侧丘脑的主要神经联系，本研究验证了丘脑核团的不同聚集体有助于独立记忆系统的假设。病变的前丘脑聚集体（AT），其中包括前背，前内侧和前腹侧核产生大量的赤字，在工作和参考空间记忆在大鼠的径向臂迷宫任务，支持的观点，即AT是海马记忆系统的一个组成部分。外侧丘脑聚集体（LT）病变，包括板内核（中央外侧核、中央旁核和吻侧中央内侧核）和外侧背内侧丘脑核（外侧核和间板核）仅产生轻度的工作记忆障碍，而丘脑后内侧聚集体（MT）的损伤，包括丘脑中央核和内侧背内侧核，并且背内侧核对桡臂迷宫性能没有影响。相比之下，只有MT损害与奖励价值记忆相关的学习，这与MT有助于杏仁核记忆系统的观点一致。与机会歧视相比，控制组和AT组，但不是MT或LT组，表现出证据的时间顺序记忆的两个最近提出的对象，所有组都表现出完整的对象识别新与熟悉的对象。这些新的分离表明，不同的内侧丘脑聚集体参与多个记忆系统，并加强了这样一种想法，即间脑性遗忘症的记忆缺陷可能会因不同丘脑区域的相对参与而异。
Variable neuropathology in cases of diencephalic amnesia has led to uncertainty in identifying key thalamic nuclei and their potential role in learning and memory. Based on the principal neural connections of the medial thalamus, the current study tested the hypothesis that different aggregates of thalamic nuclei contribute to separate memory systems. Lesions of the anterior thalamic aggregate (AT), which comprises the anterodorsal, anteromedial and anteroventral nuclei produced substantial deficits in both working and reference spatial memory in a radial arm maze task in rats, supporting the view that the AT is an integral part of a hippocampal memory system. Lesions to the lateral thalamic aggregate (LT), which comprises the intralaminar nuclei (centrolateral, paracentral and rostral central medial nuclei) and lateral mediodorsal thalamic nuclei (lateral and paralamellar nuclei) produced a mild working memory impairment only, while lesions to the posteromedial thalamic aggregate (MT), which comprises the central and medial mediodorsal thalamic nuclei and the intermediodorsal nucleus had no effect on radial arm maze performance. In contrast, only MT lesions impaired learning associated with memory for reward value, consistent with the idea that the MT contributes to an amygdala memory system. Compared with chance discrimination, the control and AT groups, but not MT or LT groups, showed evidence for temporal order memory for two recently presented objects; all groups showed intact object recognition for novel vs. familiar objects. These new dissociations show that different medial thalamic aggregates participate in multiple memory systems and reinforce the idea that memory deficits in diencephalic amnesics may vary as a function of the relative involvement of different thalamic regions.