Departamento de Matemática Aplicada, Universidad Complutense de Madrid, Avenida Complutense s/n, 28040 Madrid, Spain.
Comput Intell Neurosci. 2010;2010:340541. doi: 10.1155/2010/340541. Epub 2010 Jan 6.
Sensory information handling is an essentially nonstationary process even under a periodic stimulation. We show how the time evolution of ridges in the wavelet spectrum of spike trains can be used for quantification of the dynamical stability of the neuronal responses to a stimulus. We employ this method to study neuronal responses in trigeminal nuclei of the rat provoked by tactile whisker stimulation. Neurons from principalis (Pr5) and interpolaris (Sp5i) show the maximal stability at the intermediate (50 ms) stimulus duration, whereas Sp5o cells "prefer" shorter (10 ms) stimulation. We also show that neurons in all three nuclei can perform as stimulus frequency filters. The response stability of about 33% of cells exhibits low-pass frequency dynamics. About 57% of cells have band-pass dynamics with the optimal frequency at 5 Hz for Pr5 and Sp5i, and 4 Hz for Sp5o, and the remaining 10% show no prominent dependence on the stimulus frequency. This suggests that the neural coding scheme in trigeminal nuclei is not fixed, but instead it adapts to the stimulus characteristics.
感觉信息处理即使在周期性刺激下也是一个本质上的非平稳过程。我们展示了如何利用尖峰序列小波谱中脊的时间演化来量化神经元对刺激的动态稳定性。我们采用这种方法来研究大鼠三叉神经核中由触须刺激引起的神经元反应。来自主核（Pr5）和中间核（Sp5i）的神经元在中间（50ms）刺激持续时间下表现出最大的稳定性，而 Sp5o 细胞“更喜欢”较短的（10ms）刺激。我们还表明，三个核中的神经元都可以作为刺激频率滤波器。约 33%的细胞的反应稳定性表现出低通频率动力学。约 57%的细胞具有带通动力学，Pr5 和 Sp5i 的最佳频率为 5Hz，Sp5o 为 4Hz，其余 10%的细胞对刺激频率没有明显的依赖性。这表明三叉神经核中的神经编码方案不是固定的，而是适应刺激的特征。
