The Spinal Control of Backward Locomotion

Area of Science:

• Neuroscience
• Locomotion Biology
• Spinal Cord Research

Background:

• Animal locomotion involves complex movements, including changes in direction like backward motion.
• Understanding the neural control of locomotion is crucial for neuroscience and rehabilitation.
• The spinal cord's role in generating different locomotor patterns is a key area of investigation.

Purpose of the Study:

• To test the hypothesis that spinal sensorimotor circuits generate backward locomotion.
• To investigate how spinal circuits adjust backward locomotion to task demands.
• To determine if spinal circuits for forward and backward locomotion are shared.

Main Methods:

• Collected kinematic and electromyography (EMG) data from adult cats during forward and backward locomotion.
• Performed experiments before and after complete spinal transection.
• Utilized treadmill locomotion, including split-belt conditions, and perineal stimulation.

Main Results:

• Spinal cats, with perineal stimulation, predominantly performed backward locomotion after spinalization.
• Spatiotemporal adjustments for speed in backward locomotion were similar to forward locomotion.
• Muscle activation patterns and muscle synergies were similar for forward and backward locomotion in spinal cats.
• Five shared muscle synergies were identified for both forward and backward locomotion.

Conclusions:

• Spinal sensorimotor circuits generate backward locomotion, requiring increased excitability compared to forward locomotion.
• Shared spinal locomotor networks likely control both forward and backward locomotion, with sensory feedback directing the pattern.
• These findings highlight the adaptability and shared neural resources within the spinal cord for motor control.