Sziklas V, Petrides M
Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada H3A 2B4.
Hippocampus. 2007;17(6):456-61. doi: 10.1002/hipo.20286.
The anterior thalamic region is intimately linked anatomically and functionally with the hippocampus, which is critical for various forms of spatial learning. Rats with lesions to the anterior thalamic nuclei and a control group were trained on a visual-spatial conditional associative learning task in which they had to learn to go to one of two locations depending on the particular visual cue presented on each trial; the rats approached the cues from different directions. The animals were subsequently tested on a spatial working memory task, the eight-arm radial maze. Performance on both these tasks had previously been shown to be impaired by hippocampal lesions. Rats with anterior thalamic damage were able to acquire the conditional associative task at a rate comparable to that of the control animals, but were impaired on the radial maze task. The finding of a dissociation between the effects of lesions of the anterior thalamic nuclei on two different classes of behavior known to be associated with hippocampal function suggest that while different neural stations within the extended hippocampal circuit may all play a role in spatial learning, the role of each of these regions in such learning may be more selective than previously considered.
丘脑前区在解剖学和功能上与海马体紧密相连，而海马体对于各种形式的空间学习至关重要。对丘脑前核损伤的大鼠和一个对照组进行视觉空间条件性联想学习任务训练，在该任务中，它们必须根据每次试验呈现的特定视觉线索学会前往两个位置之一；大鼠从不同方向接近线索。随后，对这些动物进行空间工作记忆任务测试，即八臂放射状迷宫测试。此前已表明，这两项任务的表现都会因海马体损伤而受损。丘脑前损伤的大鼠能够以与对照动物相当的速度习得条件性联想任务，但在放射状迷宫任务中表现受损。丘脑前核损伤对已知与海马体功能相关的两类不同行为产生不同影响，这一发现表明，虽然扩展海马体回路中的不同神经位点可能都在空间学习中发挥作用，但这些区域在这种学习中的作用可能比之前认为的更具选择性。
