Abstract
In the study of the neural control of rhythmic motor acts, the operation of the central neuronal networks that produce the motor pattern is an area of considerable interest (cf. Delcomyn, 1980; Grillner, 1981). The motor pattern underlying swimming in the lamprey, a primitive vertebrate, can be produced in the isolated spinal cord in vitro (Cohen & Wallén, 1980; Wallén & Williams, 1984). The capacity to generate the rhythmic pattern is distributed throughout the spinal cord, and short pieces of just a few segments may produce a coordinated pattern (Cohen & Wallén, 1980; Grillner & Sigvardt, in Grillner et al. 1982).