Application of the mathematics of coupled oscillator systems to the analysis of the neural control of locomotion.

In many animals, the activities of limb motor neurons are rhythmic during locomotion. In some animals it is known that each limb is innervated by a local control center that resides in a discrete portion of the central nervous system. Each local control center is a biological oscillator. Since each limb moves with the same frequency as each other limb and with regulated phase delay with respect to each other limb, then it follows that the local control centers are coupled to one another. The locomotory pattern generator within the central nervous system is therefore a coupled oscillator system. The mathematics of coupled oscillator systems can assist in the construction of a model of the neural pattern generator. This model can be utilized to formulate testable predictions concerning the neural control of locomotion. Experimental data gathered from organisms in several phylums are consistent with the predictions of the model.