thesis
Locomotion in the cat : a behavioural and neurophysiological study of interlimb coordination
- Publication date
- 28 April 1976
- Publisher
- The alternating periods of flexion and extension movements at
the different joints farm the elements of the locomotor cycle, which
may be adapted in force and timing to satisfy the requirements for
support of the body, balance and direction of progression.
These basic elements of movement are produced by the activities
of interneurones and moteneurones lying in the respective spinal
segments innervating each limb. In his study of narcosis progression
in the cat Brown (20) suggested that the flexion and extension
movernents were generated by groups of rieurones driving the
respective motoneurons. These groups were organized into functional
half eentres producing the signals necessary for the flexion and
extension phases of stepping by virtue of mutual inhibition. The
existence of half eentres received some confirmatien by Lundberg and
hi.s collaborators in studies on the effects of L-DOPA on spinal cord
reflexes (82). Thè actual mechanisms by which the groups of interneurones
produce phases of flexor and extensor activity have not yet
been defined, although Grillner (62) and Pearson (I 15) have suggested
some possible models.