Elliott T, Shadbolt N R
University of Nottingham, Department of Psychology, Nottingham, NG7 2RD, UK.
Neural Comput. 1998 Nov 15;10(8):1939-81. doi: 10.1162/089976698300016927.
Neurotrophic factors, particularly the neurotrophin gene family of neurotrophic factors, are implicated in activity-dependent anatomical plasticity in the visual cortex and at the neuromuscular junction. Accumulating evidence implicates neurotrophic factors as possible mediators of activity-dependent competition between afferents, leading to the segregation of afferents' arbors on the target space. We present a biologically plausible mathematical model of competition for neurotrophic factors. We show that the model leads to anatomical segregation, provided that the levels of neurotrophic factors released in an activity-independent manner, or the levels available by exogenous infusion, are below a critical value, which we derive. Above this critical value, afferent segregation breaks down. We also show that the model segregates afferents even in the presence of very highly correlated patterns of afferent activity. The model is therefore ideally suited for application to the development of ocular dominance columns in the kitten visual cortex.
神经营养因子，尤其是神经营养因子的神经营养素基因家族，与视觉皮层和神经肌肉接头处的活动依赖性解剖可塑性有关。越来越多的证据表明，神经营养因子可能是传入神经元之间活动依赖性竞争的介质，导致传入神经元树突在靶空间上的分离。我们提出了一个关于神经营养因子竞争的生物学上合理的数学模型。我们表明，只要以与活动无关的方式释放的神经营养因子水平，或通过外源注入可得的水平低于我们推导得出的临界值，该模型就会导致解剖学上的分离。高于这个临界值，传入神经元的分离就会瓦解。我们还表明，即使在传入神经元活动模式高度相关的情况下，该模型也能分离传入神经元。因此，该模型非常适合应用于小猫视觉皮层中眼优势柱的发育研究。
