Cohen A H
Division of Biological Sciences, Cornell University, Ithaca, NY 14853.
J Neurosci Methods. 1987 Oct;21(2-4):113-25. doi: 10.1016/0165-0270(87)90109-9.
The central pattern generator (CPG) for locomotion can be thought of as a chain of segmental oscillators coupled together that produces the basic locomotor pattern. The isolated spinal cord of the lamprey is an excellent preparation in which to formulate general principles for the operation of the CPG. The stability of the preparation and the ease with which surgical lesions can be made in the cord have allowed the study of the coordinating system with a convenience unobtainable in more complex vertebrates. Mathematical models have been developed to help analyze the CPG and other systems of coupled oscillators. The models have pointed to two important parameters for determining the relative timing of a system of coupled oscillators: the nature of the coupling and the difference in frequency among the oscillators. The latter is dealt with here. In lampreys, the frequency differences of the segmental oscillators along the cord can be quite large. This factor is shown to be related to changes in the intersegmental phase lags during serotonin modulation of fictive swimming. An understanding of some effects of the frequency difference is also shown to have been important in helping to formulate a protocol for the demonstration of functional regeneration in the isolated spinal cord preparation.
用于运动的中枢模式发生器（CPG）可被视为由耦合在一起的节段性振荡器组成的链条，它产生基本的运动模式。七鳃鳗的离体脊髓是一个很好的实验标本，可用于阐述CPG运作的一般原理。该标本的稳定性以及在脊髓中制造手术损伤的便利性，使得对协调系统的研究变得更加容易，而这在更复杂的脊椎动物中是无法实现的。已经开发了数学模型来帮助分析CPG和其他耦合振荡器系统。这些模型指出了两个决定耦合振荡器系统相对时间的重要参数：耦合的性质以及振荡器之间的频率差异。本文讨论的是后者。在七鳃鳗中，沿脊髓的节段性振荡器的频率差异可能相当大。这一因素被证明与在5-羟色胺调节虚构游泳期间节段间相位滞后的变化有关。对频率差异的一些影响的理解在帮助制定在离体脊髓标本中证明功能再生的方案方面也很重要。
