Tran-Van-Minh Alexandra, Cazé Romain D, Abrahamsson Therése, Cathala Laurence, Gutkin Boris S, DiGregorio David A
Unit of Dynamic Neuronal Imaging, Department of Neuroscience, CNRS UMR 3571, Institut Pasteur Paris, France.
Group for Neural Theory, LNC INSERM U960, Institut d'Etude de la Cognition de l'Ecole normale supérieure, Ecole normale supérieure Paris, France ; Department of Bioengineering, Imperial College London London, UK.
Front Cell Neurosci. 2015 Mar 24;9:67. doi: 10.3389/fncel.2015.00067. eCollection 2015.
Nonlinear dendritic integration is thought to increase the computational ability of neurons. Most studies focus on how supralinear summation of excitatory synaptic responses arising from clustered inputs within single dendrites result in the enhancement of neuronal firing, enabling simple computations such as feature detection. Recent reports have shown that sublinear summation is also a prominent dendritic operation, extending the range of subthreshold input-output (sI/O) transformations conferred by dendrites. Like supralinear operations, sublinear dendritic operations also increase the repertoire of neuronal computations, but feature extraction requires different synaptic connectivity strategies for each of these operations. In this article we will review the experimental and theoretical findings describing the biophysical determinants of the three primary classes of dendritic operations: linear, sublinear, and supralinear. We then review a Boolean algebra-based analysis of simplified neuron models, which provides insight into how dendritic operations influence neuronal computations. We highlight how neuronal computations are critically dependent on the interplay of dendritic properties (morphology and voltage-gated channel expression), spiking threshold and distribution of synaptic inputs carrying particular sensory features. Finally, we describe how global (scattered) and local (clustered) integration strategies permit the implementation of similar classes of computations, one example being the object feature binding problem.
非线性树突整合被认为可增强神经元的计算能力。大多数研究聚焦于单个树突内成簇输入所产生的兴奋性突触反应的超线性总和如何导致神经元放电增强,从而实现诸如特征检测等简单计算。最近的报告表明,亚线性总和也是一种突出的树突操作,扩展了树突赋予的阈下输入 - 输出(sI/O)转换范围。与超线性操作一样,亚线性树突操作也增加了神经元计算的种类,但特征提取对于这些操作中的每一种都需要不同的突触连接策略。在本文中,我们将回顾描述树突操作的三个主要类别(线性、亚线性和超线性)的生物物理决定因素的实验和理论发现。然后,我们回顾基于布尔代数对简化神经元模型的分析,这为深入了解树突操作如何影响神经元计算提供了思路。我们强调神经元计算如何关键地依赖于树突特性(形态和电压门控通道表达)、放电阈值以及携带特定感觉特征的突触输入分布之间的相互作用。最后,我们描述全局(分散)和局部(成簇)整合策略如何允许实现类似类别的计算,一个例子是物体特征绑定问题。