Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA; Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, IL 60208, USA; Allen Institute for Brain Science, Seattle, WA 98103, USA.
Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA.
Neuron. 2013 Dec 18;80(6):1451-63. doi: 10.1016/j.neuron.2013.09.027.
Neuronal computation involves the integration of synaptic inputs that are often distributed over expansive dendritic trees, suggesting the need for compensatory mechanisms that enable spatially disparate synapses to influence neuronal output. In hippocampal CA1 pyramidal neurons, such mechanisms have indeed been reported, which normalize either the ability of distributed synapses to drive action potential initiation in the axon or their ability to drive dendritic spiking locally. Here we report that these mechanisms can coexist, through an elegant combination of distance-dependent regulation of synapse number and synaptic expression of AMPA and NMDA receptors. Together, these complementary gradients allow individual dendrites in both the apical and basal dendritic trees of hippocampal neurons to operate as facile computational subunits capable of supporting both global integration in the soma/axon and local integration in the dendrite.
神经元计算涉及到突触输入的整合，而这些输入通常分布在广阔的树突上，这表明需要补偿机制来使空间上离散的突触能够影响神经元的输出。在海马 CA1 锥体神经元中，确实已经报道了这种机制，它可以使分布式突触驱动轴突中动作电位起始的能力或其驱动树突棘状放电的能力正常化。在这里，我们通过突触数量的距离依赖性调节和 AMPA 和 NMDA 受体的突触表达的巧妙结合，报告了这些机制可以共存。这些互补的梯度使得海马神经元的树突和基底树突中的单个树突都可以作为易于计算的子单元，既能在胞体/轴突中进行全局整合，也能在树突中进行局部整合。
