Lee Inah, Kesner Raymond P
Department of Neurobiology, University of Texas Houston Medical School, Houston, Texas 77025, USA.
J Neurosci. 2003 Feb 15;23(4):1517-23. doi: 10.1523/JNEUROSCI.23-04-01517.2003.
The prefrontal cortex and the dorsal hippocampus have been studied extensively for their significant roles in spatial working memory. A possible time-dependent functional relationship between the prefrontal cortex and the dorsal hippocampus in spatial working memory was tested. A combined lesion and pharmacological inactivation technique targeting both the dorsal hippocampus and the medial prefrontal cortex was used (i.e., axon-sparing lesions of the dorsal hippocampus combined with reversible inactivation of the medial prefrontal cortex, or vice versa, within a subject). A delayed nonmatching-to-place task on a radial eight-arm maze with short-term (i.e., 10 sec) versus intermediate-term (i.e., 5 min) delays was used as a behavioral paradigm. Here we report that the dorsal hippocampus and the medial prefrontal cortex process short-term spatial memory in parallel, serving as a compensatory mechanism for each other. The role of the dorsal hippocampus, however, becomes highlighted as the time-window for memory (i.e., delay) shifts from short-term to a delay period (i.e., intermediate-term) exceeding the short-term range. The results indicate that the time window of memory is a key factor in dissociating multiple memory systems.
前额叶皮质和背侧海马体因其在空间工作记忆中的重要作用而受到广泛研究。我们测试了前额叶皮质和背侧海马体在空间工作记忆中可能存在的时间依赖性功能关系。我们采用了一种针对背侧海马体和内侧前额叶皮质的联合损伤和药理学失活技术（即，在同一实验对象体内，背侧海马体的轴突保留性损伤与内侧前额叶皮质的可逆性失活相结合，反之亦然）。在一个具有短期（即10秒）和中期（即5分钟）延迟的放射状八臂迷宫上进行延迟非匹配位置任务，以此作为行为范式。在此我们报告，背侧海马体和内侧前额叶皮质并行处理短期空间记忆，彼此作为一种补偿机制。然而，随着记忆的时间窗口（即延迟）从短期转变为超过短期范围的延迟期（即中期），背侧海马体的作用变得突出。结果表明，记忆的时间窗口是区分多个记忆系统的关键因素。
