School of Physics, University of Sydney, Sydney, NSW 2006, Australia.
J Theor Biol. 2011 Sep 21;285(1):156-63. doi: 10.1016/j.jtbi.2011.06.023. Epub 2011 Jul 18.
Plasticity is crucial to neural development, learning, and memory. In the common in vivo situation where postsynaptic neural activity results from multiple presynaptic inputs, it is shown that a widely used class of correlation-dependent and spike-timing dependent plasticity rules can be written in a form that can be incorporated into neural field theory, which enables their system-level dynamics to be investigated. It is shown that the resulting plasticity dynamics depends strongly on the stimulus spectrum via overall system frequency responses. In the case of perturbations that are approximately linear, explicit formulas are found for the dynamics in terms of stimulus spectra via system transfer functions. The resulting theory is applied to a simple model system to reveal how collective effects, especially resonances, can drastically modify system-level plasticity dynamics from that implied by single-neuron analyses. The simplified model illustrates the potential relevance of these effects in applications to brain stimulation, synaptic homeostasis, and epilepsy.
可塑性对于神经发育、学习和记忆至关重要。在常见的体内情况中，突触后神经活动是由多个突触前输入产生的，研究表明，一类广泛使用的相关依赖和尖峰时间依赖可塑性规则可以以一种可以纳入神经场理论的形式来表示，这使得可以研究它们的系统级动态。结果表明，通过整体系统频率响应，可塑性动力学强烈依赖于刺激谱。在近似线性的情况下，通过系统传递函数找到了刺激谱方面的动力学的显式公式。所得到的理论应用于一个简单的模型系统，以揭示集体效应，特别是共振，如何从单神经元分析所暗示的系统水平可塑性动力学中急剧改变。简化模型说明了这些效应在脑刺激、突触稳态和癫痫应用中的潜在相关性。
