Young Joshua M, Waleszczyk Wioletta J, Wang Chun, Calford Michael B, Dreher Bogdan, Obermayer Klaus
Neural Information Processing Group, Department of Electrical Engineering and Computer Science, Berlin University of Technology, FR 2-1, Franklinstrasse 28/29, D-10587 Berlin, Germany.
Nat Neurosci. 2007 Jul;10(7):887-95. doi: 10.1038/nn1913. Epub 2007 May 27.
The receptive fields of neurons in primary visual cortex that are inactivated by retinal damage are known to 'shift' to nondamaged retinal locations, seemingly due to the plasticity of intracortical connections. We have observed in cats that these shifts occur in a pattern that is highly convergent, even among receptive fields that are separated by large distances before inactivation. Here we show, using a computational model of primary visual cortex, that the observed convergent shifts are inconsistent with the common assumption that the underlying intracortical connection plasticity is dependent on the temporal correlation of pre- and postsynaptic action potentials. The shifts are, however, consistent with the hypothesis that this plasticity is dependent on the temporal order of pre- and postsynaptic action potentials. This convergent reorganization seems to require increased neuronal gain, revealing a mechanism that networks may use to selectively facilitate the didactic transfer of neuronal response properties.
已知因视网膜损伤而失活的初级视觉皮层中神经元的感受野会“转移”到未受损的视网膜位置，这似乎是由于皮质内连接的可塑性所致。我们在猫身上观察到，这些转移以高度汇聚的模式发生，即使在失活前相距很远的感受野之间也是如此。在这里，我们使用初级视觉皮层的计算模型表明，观察到的汇聚转移与一种常见假设不一致，该假设认为潜在的皮质内连接可塑性取决于突触前和突触后动作电位的时间相关性。然而，这些转移与另一种假设一致，即这种可塑性取决于突触前和突触后动作电位的时间顺序。这种汇聚性重组似乎需要增加神经元增益，揭示了一种神经网络可能用于选择性促进神经元反应特性的教学性传递的机制。
