Descending and Ascending Signals That Maintain Rhythmic Walking Pattern in Crickets

Area of Science:

• Neuroscience
• Animal Locomotion
• Insect Behavior

Background:

• Crickets utilize a tripod gait for locomotion, controlled by thoracic ganglia.
• Understanding neural control of insect walking is crucial for adaptive locomotion research.

Purpose of the Study:

• To investigate the role of descending and ascending neural signals in coordinating cricket walking gait.
• To elucidate the neuronal mechanisms underlying adaptive locomotion in insects.

Main Methods:

• Surgical cutting of cricket ventral nerve cords and specific neural connectives.
• Observation and analysis of resulting walking gait patterns.

Main Results:

• Cutting circumesophageal connectives (brain to subesophageal ganglion) maintained tripod gait, but unilateral cuts caused turning.
• Severing SEG to prothoracic ganglion connectives abolished walking; intact unilateral connectives allowed tripod gait.
• Cutting metathoracic ganglion to abdominal ganglia connectives resulted in uncoordinated walking; intact unilateral connectives allowed tripod gait.

Conclusions:

• The brain appears to have an inhibitory role in initiating leg movements.
• Both descending (head) and ascending (abdominal) neural signals are vital for initiating and coordinating insect walking gait.