Retrospective and prospective responses arising in a modeled hippocampus during maze navigation by a brain-based device
Retrospective and prospective responses arising in a modeled hippocampus during maze navigation by a brain-based device
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DOI：
10.1073/pnas.0611571104
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发表时间：
2007-02-27
影响因子：
11.1
通讯作者：
Krichmar, Jeffrey L.
中科院分区：
文献类型：
--
作者：
Fleischer, Jason G.;Gally, Joseph A.;Krichmar, Jeffrey L.
最近啮齿动物海马体的位置场活动记录揭示了空间记忆任务中当前、最近的过去和即将发生的未来事件的相关性。为了分析这些特性，我们使用了一个基于大脑的设备，Darwin XI，它包含了一个由经验依赖的突触活动形成的内侧颞结构的详细模型。达尔文11号在一个正迷宫中进行了测试，它从不同的起始臂接近目标臂。在任务中，旅程对应于从特定起点到特定目标的路线。在迷宫导航过程中，该装置在其模拟的海马体中产生了位置依赖性反应。在模拟的ca1神经元单元的记录中发现，在通过同一迷宫臂的不同旅程中，其活动不同的路程依赖地点场。我们还发现了大约相同数量的与旅程无关的地点场。路程依赖性反应要么是回顾性的，即活动出现在目标组，要么是前瞻性的，即活动出现在开始组。对行为过程中神经模拟网络动力学的详细分析表明，许多不同的神经通路可以刺激任何一个CA1单元。该分析还显示，位置活动更多地受到海马和内嗅皮层的影响，而不是感觉皮层的输入。此外，海马体对旅行依赖型活动的影响比旅行独立型活动更强烈。
Recent recordings of place field activity in rodent hippocampus have revealed correlates of current, recent past, and imminent future events in spatial memory tasks. To analyze these properties, we used a brain-based device, Darwin XI, that incorporated a detailed model of medial temporal structures shaped by experience-dependent synaptic activity. Darwin XI was tested on a plus maze in which it approached a goal arm from different start arms. In the task, a journey corresponded to the route from a particular starting point to a particular goal. During maze navigation, the device developed place-dependent responses in its simulated hippocampus. Journey-dependent place fields, whose activity differed in different journeys through the same maze arm, were found in the recordings of simulated CA 1 neuronal units. We also found an approximately equal number of journey-independent place fields. The journey-dependent responses were either retrospective, where activity was present in the goal arm, or prospective, where activity was present in the start arm. Detailed analysis of network dynamics of the neural simulation during behavior revealed that many different neural pathways could stimulate any single CA1 unit. That analysis also revealed that place activity was driven more by hippocampal and entorhinal cortical influences than by sensory cortical input. Moreover, journey-dependent activity was driven more strongly by hippocampal influence than journey-independent activity.