Floresco S B, Seamans J K, Phillips A G
Department of Psychology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4.
J Neurosci. 1997 Mar 1;17(5):1880-90. doi: 10.1523/JNEUROSCI.17-05-01880.1997.
The hippocampus, the prefrontal cortex, and the ventral striatum form interconnected neural circuits that may underlie aspects of spatial cognition and memory. In the present series of experiments, we investigated functional interactions between these areas in rats during the performance of delayed and nondelayed spatially cued radial-arm maze tasks. The two-phase delayed task consisted of a training phase that provided rats with information about where food would be located on the maze 30 min later during a test phase. The single-phase nondelayed task was identical to the test phase of the delayed task, but in the absence of a training phase rats lacked previous knowledge of the location of food on the maze. Transient inactivation of the ventral CA1/subiculum (vSub) by a bilateral injection of lidocaine disrupted performance on both tasks. Lidocaine injections into the vSub on one side of the brain and the prefrontal cortex on the other transiently disconnected these two brain regions and significantly impaired foraging during the delayed task but not the nondelayed task. Transient disconnections between the vSub and the nucleus accumbens produced the opposite effect, disrupting foraging during the nondelayed task but not during the delayed task. These data suggest that serial transmission of information between the vSub and the prefrontal cortex is required when trial-unique, short-term memory is used to guide prospective search behavior. In contrast, exploratory goal-directed locomotion in a novel situation not requiring previously acquired information about the location of food is dependent on serial transmission between the hippocampus and the nucleus accumbens. These results indicate that different aspects of spatially mediated behavior are subserved by separate, distributed limbic-cortical-striatal networks.
海马体、前额叶皮质和腹侧纹状体形成相互连接的神经回路，这些回路可能是空间认知和记忆方面的基础。在本系列实验中，我们研究了大鼠在执行延迟和非延迟空间线索放射状臂迷宫任务时，这些区域之间的功能相互作用。两阶段延迟任务包括一个训练阶段，该阶段为大鼠提供关于在测试阶段30分钟后食物将位于迷宫何处的信息。单阶段非延迟任务与延迟任务的测试阶段相同，但在没有训练阶段的情况下，大鼠缺乏关于迷宫中食物位置的先前知识。通过双侧注射利多卡因对腹侧CA1/下托（vSub）进行短暂失活，破坏了两项任务的表现。在大脑一侧的vSub和另一侧的前额叶皮质注射利多卡因，暂时断开了这两个脑区的连接，并在延迟任务期间显著损害了觅食行为，但在非延迟任务中没有。vSub和伏隔核之间的短暂断开产生了相反的效果，破坏了非延迟任务期间的觅食行为，但在延迟任务期间没有。这些数据表明，当使用试验独特的短期记忆来指导前瞻性搜索行为时，vSub和前额叶皮质之间需要信息的串行传输。相比之下，在不需要先前获取的食物位置信息的新情境中，探索性目标导向的运动依赖于海马体和伏隔核之间的串行传输。这些结果表明，空间介导行为的不同方面由单独的、分布式的边缘-皮质-纹状体网络支持。
