Models of central pattern generators for quadruped locomotion. II. Secondary gaits

Area of Science:

• Neuroscience
• Dynamical Systems
• Locomotion

Background:

• Central pattern generators (CPGs) are neural circuits controlling rhythmic behaviors like locomotion.
• Previous work modeled quadruped locomotion using symmetrically coupled cells.
• Secondary gaits, such as transverse gallop and rotary gallop, are less understood than primary gaits.

Purpose of the Study:

• To analyze secondary gaits in a CPG model for quadruped locomotion.
• To classify secondary gaits that bifurcate from primary gaits.
• To investigate period-doubling bifurcations and their resulting footfall patterns.

Main Methods:

• Studied secondary gaits modeled by CPG output signals with phase shifts.
• Classified gaits based on eigenvalues of the Poincaré map.
• Employed numerical simulations using Morris-Lecar equations for cell dynamics.

Main Results:

• Periodic solutions modeling transverse gallop and rotary gallop were shown to bifurcate from primary gaits.
• New gaits arising from period-doubling bifurcations were identified.
• Plausible footfall patterns for these novel gaits were analyzed.

Conclusions:

• The study provides a classification of secondary gaits in CPG models.
• Bifurcation analysis successfully predicts the emergence of specific gaits like transverse and rotary gallop.
• Period-doubling bifurcations offer a mechanism for generating diverse locomotion patterns in quadrupedal animals.