Mechanisms of coupling between the ipsilateral legs of a walking insect (Carausius morosus)

Summary The mechanisms by which the legs of a stick insect influence one another during walking were investigated by running the animals on a horizontal plane covered with a thin film of silicone oil to prevent mechanical coupling between the legs. Coupling between ipsilateral legs was investigated by interrupting the retraction (power stroke) of a leg for a short time and observing how the legs return to normal coordination following this disturbance. The results show that three ipsilateral coupling mechanisms exist: (a) a forwarddirected influence that inhibits the start of a protraction of the leg as long as the posterior leg is performing a protraction; (b) a forward-directed influence that excites the start of a protraction of the leg when the posterior leg starts a retraction movement; (c) a backward-directed influence that excites the start of a protraction, the influence being stronger the further the anterior leg has moved backwards during its retraction. The latter influence depends on the position but not the phase of the anterior leg.

[1]  K. Pearson.  Central Programming and Reflex Control of Walking in the Cockroach , 1972 .

[2]  K. Pearson,et al.  Nervous Mechanisms Underlying Intersegmental Co-Ordination of Leg Movements During Walking in the Cockroach , 1973 .

[3]  D. Graham.  UNUSUAL STEP PATTERNS IN THE FREE WALKING •GRASSHOPPER NEOCONOCEPHALUS ROBUSTUS II. A CRITICAL TEST OF THE LEG INTERACTIONS UNDERLYING DIFFERENT MODELS OF HEXAPOD CO-ORDINATION , 1978 .

[4]  U. Bässler.  Interaction of central and peripheral mechanisms during walking in first instar stick insects, Extatosoma tiaratum , 1979 .

[5]  H. Cruse.  The control of the anterior extreme position of the hindleg of a walking insect, Carausius morosus , 1979 .

[6]  H. Cruse,et al.  Peripheral Influences on the Movement of the Legs in a Walking Insect Carausius Morosus , 1982 .

[7]  D. Graham,et al.  Behaviour and Motor Output of Stick Insects Walking on a Slippery Surface: I. Forward Walking , 1983 .

[8]  U. Bässler,et al.  Motor Output of the Denervated Thoracic Ventral Nerve Cord in the Stick Insect Carausius Morosus , 1983 .

[9]  D H Godden,et al.  'Instant' analysis of movement. , 1983, The Journal of experimental biology.

[10]  J. Dean,et al.  Stick Insect Locomotion on a Walking Wheel: Interleg Coordination of Leg Position , 1983 .

[11]  H. Cruse.  Which parameters control the leg movement of a walking insect? II: The start of the swing phase , 1985 .

[12]  H. Cruse.  Coactivating Influences Between Neighbouring Legs in Walking Insects , 1985 .

[13]  H. Cruse,et al.  Two coupling mechanisms which determine the coordination of ipsilateral legs in the walking crayfish , 1986 .