Achard Pablo, De Schutter Erik
Theoretical Neurobiology, University of Antwerp, Belgium.
PLoS Comput Biol. 2006 Jul 21;2(7):e94. doi: 10.1371/journal.pcbi.0020094.
The electrical activity of a neuron is strongly dependent on the ionic channels present in its membrane. Modifying the maximal conductances from these channels can have a dramatic impact on neuron behavior. But the effect of such modifications can also be cancelled out by compensatory mechanisms among different channels. We used an evolution strategy with a fitness function based on phase-plane analysis to obtain 20 very different computational models of the cerebellar Purkinje cell. All these models produced very similar outputs to current injections, including tiny details of the complex firing pattern. These models were not completely isolated in the parameter space, but neither did they belong to a large continuum of good models that would exist if weak compensations between channels were sufficient. The parameter landscape of good models can best be described as a set of loosely connected hyperplanes. Our method is efficient in finding good models in this complex landscape. Unraveling the landscape is an important step towards the understanding of functional homeostasis of neurons.
神经元的电活动强烈依赖于其膜中存在的离子通道。改变这些通道的最大电导会对神经元行为产生巨大影响。但是这种改变的效果也可能被不同通道之间的补偿机制抵消。我们使用了一种基于相平面分析的适应度函数的进化策略，来获得20个非常不同的小脑浦肯野细胞计算模型。所有这些模型对电流注入产生了非常相似的输出，包括复杂放电模式的微小细节。这些模型在参数空间中并非完全孤立，但它们也不属于如果通道之间的弱补偿足够就会存在的一大类连续的好模型。好模型的参数格局最好被描述为一组松散连接的超平面。我们的方法在这个复杂格局中寻找好模型方面是有效的。解开这个格局是迈向理解神经元功能稳态的重要一步。
