The Involvement of Recurrent Connections in Area CA3 in Establishing the Properties of Place Fields: a Model
The Involvement of Recurrent Connections in Area CA3 in Establishing the Properties of Place Fields: a Model
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DOI：
10.1523/jneurosci.20-19-07463.2000
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发表时间：
2000-10
期刊：
影响因子：
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通讯作者：
S. Káli;P. Dayan
中科院分区：
文献类型：
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作者：
S. Káli;P. Dayan
对啮齿动物海马区位置场形成的神经机制的强烈限制来自于系统环境操作导致的空间活动模式的系统性变化。我们描述了一个CA3区的吸引子网络模型，在该模型中，局部的、经常性的、兴奋的和抑制的相互作用从内嗅皮层的位置和方向特定的活动中产生适当的位置细胞表征。在该模型中，对环境的熟悉程度，如神经调节系统中的活动所反映的，影响CA3的经常性和前馈输入的有效性和可塑性。在陌生、新奇的环境中，苔藓纤维的输入对CA3施加了活动模式，而重复的侧支和穿支路的输入受到分级的Hebbian可塑性的影响。这塑造了CA3吸引器，并将它们与内嗅觉皮质的活动模式联系起来。在熟悉的环境中，位置场由穿孔路径输入在吸引子中选择的方式控制。根据提供的训练经验，该模型生成定向或非定向的位置场，并且其在环境经历简单几何变换时的变化与实验数据一致。可以在几乎没有干扰的情况下存储和调用多个环境的表示，并且这些表示在视觉上相似的环境中具有适当程度的相似性。
Strong constraints on the neural mechanisms underlying the formation of place fields in the rodent hippocampus come from the systematic changes in spatial activity patterns that are consequent on systematic environmental manipulations. We describe an attractor network model of area CA3 in which local, recurrent, excitatory, and inhibitory interactions generate appropriate place cell representations from location- and direction-specific activity in the entorhinal cortex. In the model, familiarity with the environment, as reflected by activity in neuromodulatory systems, influences the efficacy and plasticity of the recurrent and feedforward inputs to CA3. In unfamiliar, novel, environments, mossy fiber inputs impose activity patterns on CA3, and the recurrent collaterals and the perforant path inputs are subject to graded Hebbian plasticity. This sculpts CA3 attractors and associates them with activity patterns in the entorhinal cortex. In familiar environments, place fields are controlled by the way that perforant path inputs select among the attractors. Depending on the training experience provided, the model generates place fields that are either directional or nondirectional and whose changes when the environment undergoes simple geometric transformations are in accordance with experimental data. Representations of multiple environments can be stored and recalled with little interference, and these have the appropriate degrees of similarity in visually similar environments.