Miller K D
Department of Physiology and Otolaryngology, W. M. Keck Center for Integrative Neuroscience, Sloan Center for Theoretical Neurobiology, University of California, San Francisco 94143-0444, USA.
Neural Comput. 1998 Apr 1;10(3):529-47. doi: 10.1162/089976698300017647.
A simple model of correlation-based synaptic plasticity via axonal sprouting and retraction (Elliott, Howarth, & Shadbolt, 1996a) is shown to be equivalent to the class of correlation-based models (Miller, Keller, & Stryker, 1989), although these were formulated in terms of weight modification of anatomically fixed synapses. Both models maximize the same measure of synaptic correlation, subject to certain constraints on connectivity. Thus, the analyses of the correlation-based models suffice to characterize the behavior of the sprouting-and-retraction model. More detailed models are needed for theoretical distinctions to be drawn between plasticity via sprouting and retraction, weight modification, or a combination. The model of Elliott et al. involves stochastic search through allowed weight patterns for those that improve correlations. That of Miller et al. instead follows dynamical equations that determine continuous changes of the weights that improve correlations. The identity of these two approaches is shown to depend on the use of subtractive constraint enforcement in the models of Miller et al. More generally, to model the idea that neural development acts to maximize some measure of correlation subject to a constraint on the summed synaptic weight, the constraint must be enforced subtractively in a dynamical model.
通过轴突发芽和回缩实现的基于相关性的突触可塑性的一个简单模型（Elliott、Howarth和Shadbolt，1996a）被证明等同于基于相关性的模型类别（Miller、Keller和Stryker，1989），尽管后者是根据解剖学上固定的突触的权重修改来表述的。这两个模型在连接性的某些约束条件下，最大化相同的突触相关性度量。因此，基于相关性的模型分析足以表征发芽和回缩模型的行为。要在通过发芽和回缩实现的可塑性、权重修改或两者结合之间进行理论区分，还需要更详细的模型。Elliott等人的模型涉及在允许的权重模式中进行随机搜索，以寻找那些能改善相关性的模式。而Miller等人的模型则遵循动态方程，这些方程确定能改善相关性的权重的连续变化。这两种方法的一致性被证明取决于Miller等人的模型中减法约束的实施。更一般地说，为了模拟神经发育的作用是在突触总权重的约束下最大化某种相关性度量的观点，在动态模型中必须通过减法来实施约束。
