Dumont Julie R, Aggleton John P
School of Psychology, Cardiff University, Cardiff, Wales, United Kingdom.
Behav Neurosci. 2013 Jun;127(3):415-31. doi: 10.1037/a0032750.
The anterior thalamic nuclei form part of a network for episodic memory in humans. The importance of these nuclei for recognition and recency judgments remains, however, unclear. Rats with anterior thalamic nuclei lesions and their controls were tested on object recognition, along with two types of recency judgment. The spontaneous discrimination of a novel object or a novel odor from a familiar counterpart (recognition memory) was not affected by anterior thalamic lesions when tested after retention delays of 1 and 60 min. To measure recency memory, rats were shown two familiar objects, one of which had been explored more recently. In one condition, rats were presented with two lists (List A, List B) of objects separated by a delay, thereby creating two distinct blocks of stimuli. After an additional delay, rats were presented with pairs of objects, one from List A and one from List B (between-block recency). No lesion-induced deficit was apparent for recency discriminations between objects from different lists, despite using three different levels of task difficulty. In contrast, rats with anterior thalamic lesions were significantly impaired when presented with a continuous list of objects and then tested on their ability to distinguish between those items early and late in the same list (within-block recency). The contrasting effects on recognition and recency support the notion that interlinked hippocampal-anterior thalamic interconnections support aspects of both spatial and nonspatial learning, although the role of the anterior thalamic nuclei may be restricted to a subclass of recency judgments (within-block).
丘脑前核是人类情景记忆网络的一部分。然而，这些核团对于识别和新近度判断的重要性仍不明确。对丘脑前核损伤的大鼠及其对照组进行了物体识别测试，以及两种类型的新近度判断测试。当在1分钟和60分钟的保持延迟后进行测试时，丘脑前核损伤并未影响大鼠对新物体或新气味与熟悉物体的自发辨别（识别记忆）。为了测量新近记忆，向大鼠展示两个熟悉的物体，其中一个是最近探索过的。在一种情况下，给大鼠呈现两个由延迟隔开的物体列表（列表A、列表B），从而创建两个不同的刺激块。在额外的延迟后，给大鼠呈现成对的物体，一个来自列表A，一个来自列表B（块间新近度）。尽管使用了三种不同水平的任务难度，但对于来自不同列表的物体之间的新近度辨别，损伤诱导的缺陷并不明显。相比之下，当给丘脑前核损伤的大鼠呈现一个连续的物体列表，然后测试它们区分同一列表中早期和晚期项目的能力（块内新近度）时，它们会受到显著损害。对识别和新近度的不同影响支持了这样一种观点，即相互连接的海马体 - 丘脑前核连接支持空间和非空间学习的各个方面，尽管丘脑前核的作用可能仅限于新近度判断的一个子类（块内）。
