Low dimensional attractors in discharges of sensory neurons of the rat spinal dorsal horn are maintained by supraspinal descending systems
Low dimensional attractors in discharges of sensory neurons of the rat spinal dorsal horn are maintained by supraspinal descending systems
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DOI：
10.1016/0306-4522(95)00344-i
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发表时间：
1996-01-01
期刊：
影响因子：
3.3
通讯作者：
Sandkuhler, J
中科院分区：
文献类型：
--
作者：
Debus, S;Sandkuhler, J
背景活动记录从感觉神经元层I-V的大鼠腰脊髓背角之前和期间冷阻滞脊髓在颈髓。为了图形化和定量地描述放电模式的复杂性，绘制相空间肖像，并通过使用点过程，即一系列的interspike间隔所采用的Grassberger-Procaccia算法计算关联维数D-2。该算法验证了贝克变换，这是一个简单的点过程，并为洛伦兹模型，从而实现从连续到点的过程变量的转换。提出了一种替代数据的方法，以显示原始神经元模式与其替代随机数据之间的差异。因此，这种方法表明，神经元放电模式不能完全描述的峰间期直方图。然而，在完整的脊髓中，大多数（73%）神经元显示背景活动，（0.28-4.3）D-2值。在脊髓化过程中，68%的神经元的D-2值显著增加，这些神经元先前显示出低D-2值，而与神经元的分类和层状位置无关，从而证明紧张性下行系统可能维持感觉背角神经元放电的高序性。
Background activity was recorded from sensory neurons in laminae I-V of the lumbar spinal dorsal horn of the rat prior to and during cold block spinalization at the cervical cord. To graphically and quantitatively describe the complexity of the discharge patterns, phase space portraits were plotted and the correlation dimension D-2 was calculated by using the Grassberger-Procaccia algorithm adopted for point processes, i.e. for series of interspike intervals. The algorithm is validated both for the Baker transformation, which is a simple point process, and for the Lorenz model, whereby a transformation from continuous to point process variables is achieved. A method of surrogate data is provided in order to show the difference between original neuronal patterns and their surrogate stochastic data. Therefore, this method shows that neuronal discharge patterns cannot be fully described in terms of interspike interval histograms. However, in the intact cord most (73%) of the neurons displayed background activity with low (0.28-4.3) D-2 values.During spinalization, D-2 values significantly increased in 68% of the neurons showing previously low D-2 values, irrespective of classification and laminar location of neurons, thus proving that tonic descending systems may maintain a high order in the discharge of sensory dorsal horn neurons.