Cognitive functions of intracellular mechanisms for contextual amplification
Cognitive functions of intracellular mechanisms for contextual amplification
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DOI：
10.1016/j.bandc.2015.09.005
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发表时间：
2017-03-01
影响因子：
2.5
通讯作者：
Phillips, William A.
中科院分区：
文献类型：
--
作者：
Phillips, William A.
新皮层锥体细胞的顶丛输入在认知中起着重要作用，通过放大前馈输入的反应的假设的证据进行审查。顶丛在电学上远离索马，它们的输入来自不同的来源，包括来自更高皮层区域的直接反馈，通过丘脑的间接反馈，以及皮层区域内和之间的长距离横向连接。这表明，对簇状树突的输入可能会放大细胞对基础输入的反应，这些基础输入是通过第4层接收的，并且突触更接近索马。ERP数据支持这一推论指出。顶端放大（AA）和抑制性interneurons只针对簇的解放大的细胞内研究进行了审查。认知过程，已与他们有关的计算，电生理学和精神病理学的研究，然后概述。这些程序包括：图形-背景分离和完形分组;感知和句子理解中的语境消歧;启动;赢者通吃竞争;注意力和工作记忆;设定意识水平;认知控制;和学习。有人认为，在认知神经科学的理论不应该假设所有的神经元作为集成和点火点处理器的功能，但应该使用的能力与不同的网站的集成驱动和调制输入的细胞。潜在的“统一”的理论，依赖于这些能力进行审查。它的结论是，进化的原始AA和去放大的新皮层可能有扩展的认知能力超出了那些建立了长期的原始兴奋，抑制和去抑制。(C)2015 Elsevier Inc. All rights reserved.
Evidence for the hypothesis that input to the apical tufts of neocortical pyramidal cells plays a central role in cognition by amplifying their responses to feedforward input is reviewed. Apical tufts are electrically remote from the soma, and their inputs come from diverse sources including direct feedback from higher cortical regions, indirect feedback via the thalamus, and long-range lateral connections both within and between cortical regions. This suggests that input to tuft dendrites may amplify the cell's response to basal inputs that they receive via layer 4 and which have synapses closer to the soma. ERP data supporting this inference is noted. Intracellular studies of apical amplification (AA) and of disamplification by inhibitory interneurons targeted only at tufts are reviewed. Cognitive processes that have been related to them by computational, electrophysiological, and psychopathological studies are then outlined. These processes include: figure-ground segregation and Gestalt grouping; contextual disambiguation in perception and sentence comprehension; priming; winner-take-all competition; attention and working memory; setting the level of consciousness; cognitive control; and learning. It is argued that theories in cognitive neuroscience should not assume that all neurons function as integrate-and-fire point processors, but should use the capabilities of cells with distinct sites of integration for driving and modulatory inputs. Potentially 'unifying' theories that depend upon these capabilities are reviewed. It is concluded that evolution of the primitives of AA and disamplification in neocortex may have extended cognitive capabilities beyond those built from the long-established primitives of excitation, inhibition, and disinhibition.(C) 2015 Elsevier Inc. All rights reserved.