The hippocampal-entorhinal system is important for spatial and relational memory tasks. We formally link these domains, provide a mechanistic understanding of the hippocampal role in generalization, and offer unifying principles underlying many entorhinal and hippocampal cell types. We propose medial entorhinal cells form a basis describing structural knowledge, and hippocampal cells link this basis with sensory representations. Adopting these principles, we introduce the Tolman-Eichenbaum machine (TEM). After learning, TEM entorhinal cells display diverse properties resembling apparently bespoke spatial responses, such as grid, band, border, and object-vector cells. TEM hippocampal cells include place and landmark cells that remap between environments. Crucially, TEM also aligns with empirically recorded representations in complex non-spatial tasks. TEM also generates predictions that hippocampal remapping is not random as previously believed; rather, structural knowledge is preserved across environments. We confirm this structural transfer over remapping in simultaneously recorded place and grid cells.

海马-内嗅系统对于空间和关系记忆任务很重要。我们正式将这些领域联系起来，提供对海马在泛化中的作用的机械理解，并提供许多内嗅和海马细胞类型的统一原理。我们提出内侧内嗅细胞形成描述结构知识的基础，而海马细胞将该基础与感觉表征联系起来。采用这些原理，我们引入了托尔曼-艾兴鲍姆机（TEM）。学习后，TEM 内嗅细胞表现出多种属性，类似于明显定制的空间响应，例如网格、带、边界和对象矢量细胞。 TEM 海马细胞包括在环境之间重新映射的位置细胞和地标细胞。至关重要的是，TEM 还与复杂非空间任务中经验记录的表示相一致。 TEM 还预测海马体重新映射并不像之前认为的那样是随机的；相反，结构知识是跨环境保存的。我们通过同时记录的位置和网格单元中的重新映射来确认这种结构转移。