Williams T L
Physiology Department, St. George's Hospital Medical School, University of London, United Kingdom.
Science. 1992 Oct 23;258(5082):662-5. doi: 10.1126/science.1411575.
Many neural systems behave as arrays of coupled oscillators, with characteristic phase coupling. For example, the rhythmic activation patterns giving rise to swimming in fish are characterized by a rostral-to-caudal phase delay in ventral root activity that is independent of the cycle duration. This produces a traveling wave of curvature along the body of the animal with a wavelength approximately equal to the body length. Here a simple mechanism for phase coupling in chains of equally activated oscillators is postulated: the synapses between the cells making up a "unit oscillator" are simply repeated in neighboring segments, with a reduced synaptic strength. If such coupling is asymmetric in the rostral and caudal directions, traveling waves of activity are produced. The intersegmental phase lag that develops is independent of the coupling strength over at least a tenfold range. Furthermore, for the unit oscillator believed to underlie central pattern generation in the lamprey spinal cord, such coupling can result in a phase lag that is independent of frequency.
许多神经系统表现为耦合振荡器阵列，具有特征性的相位耦合。例如，导致鱼类游泳的节律性激活模式的特征是腹根活动中从吻端到尾端的相位延迟，该延迟与周期持续时间无关。这会在动物身体上产生一个曲率行波，其波长大约等于身体长度。这里假定了一种在同等激活的振荡器链中进行相位耦合的简单机制：构成“单位振荡器”的细胞之间的突触在相邻节段中简单重复，但突触强度降低。如果这种耦合在吻端和尾端方向上不对称，就会产生活动行波。所产生的节间相位滞后在至少十倍的范围内与耦合强度无关。此外，对于被认为是七鳃鳗脊髓中央模式发生器基础的单位振荡器，这种耦合可导致与频率无关的相位滞后。
