In a changing environment, animals must process spatial signals in a flexible manner. The rat hippocampal formation projects directly upon the retrosplenial cortex, with most inputs arising from the dorsal subiculum and terminating in the granular retrosplenial cortex (area 29). The present study examined whether these same projections are required for spatial working memory and what happens when available spatial cues are altered. Consequently, injections of iDREADDs were made into the dorsal subiculum of rats. In a separate control group, GFP‐expressing adeno‐associated virus was injected into the dorsal subiculum. Both groups received intracerebral infusions within the retrosplenial cortex of clozapine, which in the iDREADDs rats should selectively disrupt the subiculum to retrosplenial projections. When tested on reinforced T‐maze alternation, disruption of the subiculum to retrosplenial projections had no evident effect on the performance of those alternation trials when all spatial‐cue types remained present and unchanged. However, the same iDREADDs manipulation impaired performance on all three alternation conditions when there was a conflict or selective removal of spatial cues. These findings reveal how the direct projections from the dorsal subiculum to the retrosplenial cortex support the flexible integration of different spatial cue types, helping the animal to adopt the spatial strategy that best meets current environmental demands.

中文翻译：

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扰乱从背下托到颗粒压后皮层的直接输入会损害大鼠灵活的空间记忆

在不断变化的环境中，动物必须以灵活的方式处理空间信号。大鼠海马结构直接投射到压后皮质，大部分输入来自背侧下托并终止于颗粒状压后皮质（区域 29）。本研究检查了空间工作记忆是否需要这些相同的预测，以及当可用的空间线索改变时会发生什么。因此，将 iDREADD 注射到大鼠的背下托中。在另一个对照组中，将表达 GFP 的腺相关病毒注射到背下托中。两组均在压后皮质内接受脑内输注氯氮平，在 iDREADD 大鼠中，氯氮平应选择性破坏下托到压后的投射。当对强化 T 迷宫交替进行测试时，当所有空间线索类型保持存在且不变时，下托到压后投影的破坏对这些交替试验的表现没有明显影响。然而，当存在冲突或选择性删除空间线索时，相同的 iDREADD 操作会损害所有三种交替条件下的性能。这些发现揭示了从背下托到压后皮层的直接投射如何支持不同空间线索类型的灵活整合，帮助动物采取最能满足当前环境需求的空间策略。