Two thalamic sites are of especial significance for understanding hippocampal – diencephalic interactions: the anterior thalamic nuclei and nucleus reuniens. Both nuclei have dense, direct interconnections with the hippocampal formation, and both are directly connected with many of the same cortical and subcortical areas. These two thalamic sites also contain neurons responsive to spatial stimuli while lesions within these two same areas can disrupt spatial learning tasks that are hippocampal dependent. Despite these many similarities, closer analysis reveals important differences in the details of their connectivity and the behavioural impact of lesions in these two thalamic sites. These nuclei play qualitatively different roles that largely reflect the contrasting relative importance of their medial frontal cortex interactions (nucleus reuniens) compared with their retrosplenial, cingulate, and mammillary body interactions (anterior thalamic nuclei). While the anterior thalamic nuclei are critical for multiple aspects of hippocampal spatial encoding and performance, nucleus reuniens contributes, as required, to aid cognitive control and help select correct from competing memories.

两个丘脑部位对于理解海马-间脑相互作用具有特别重要的意义：丘脑前核和团聚核。两个核与海马结构都有密集、直接的互连，并且都与许多相同的皮质和皮质下区域直接连接。这两个丘脑部位还包含对空间刺激敏感的神经元，而这两个相同区域内的病变可能会破坏海马依赖性的空间学习任务。尽管有许多相似之处，但更仔细的分析揭示了这两个丘脑部位的连接细节和病变对行为影响的重要差异。这些核发挥着本质上不同的作用，很大程度上反映了它们的内侧额叶皮层相互作用（团聚核）与其压后、扣带回和乳头体相互作用（丘脑前核）相比的相对重要性。虽然丘脑前核对于海马空间编码和表现的多个方面都至关重要，但团聚核根据需要有助于帮助认知控制并帮助从竞争记忆中选择正确的信息。