A Neuromechanical Model of Multiple Network Rhythmic Pattern Generators for Forward Locomotion in C. elegans

Area of Science:

• Neuroscience
• Computational Biology
• Biophysics

Background:

• Locomotion in Caenorhabditis elegans relies on rhythmic neural patterns.
• Previous research focused on pacemaker neurons and stretch-receptor feedback.
• The role of ventral nerve cord network rhythmic pattern generators remains less explored.

Purpose of the Study:

• To investigate the contribution of ventral nerve cord network rhythmic pattern generators to C. elegans locomotion.
• To identify circuit parameters enabling locomotion without pacemaker neurons or stretch-receptor feedback.

Main Methods:

• Utilized a simulation model of the anatomically constrained ventral nerve cord circuit.
• Embodied and situated the model for forward locomotion on agar.
• Systematically explored parameter space to find functional configurations.

Main Results:

• Multiple network configurations were found to drive locomotion consistent with C. elegans kinematics.
• The simulation successfully generated forward locomotion without relying on pacemaker neurons or stretch-receptor feedback.
• Analysis identified specific configurations of ventral nerve cord motorneuron networks.

Conclusions:

• The ventral nerve cord contains multiple configurations of rhythmic pattern generators capable of producing locomotion.
• Gap junctions between motorneuron classes are crucial for coordinating these generators.
• This study expands our understanding of the distributed control of C. elegans locomotion.