Cats always land on their feet, but how do they do it? Their unusual sense of balance has more in common with humans than one might think.
Researchers at the Georgia Institute of Technology are studying cat locomotion to better understand how the spinal cord works to help humans with partial spinal cord damage walk and maintain balance
Cat locomotion could unlock better human spinal cord injury treatment
Leon Neal/Getty Images
The researchers show that somatosensory feedback, or neural signals from specialized sensors throughout a cat's body, helps inform the spinal cord about ongoing movement and coordinates the four limbs to keep cats from falling when they encounter obstacles using a combination of experimental studies and computational models, as per ScienceDaily.
According to research, the animal can walk even if the connection between the spinal cord and the brain is partially fractured by using motion-related sensory signals.
Understanding the mechanisms of this type of balance control is especially important for the elderly, who frequently have balance issues and can injure themselves in falls.
The researchers hope that this will eventually lead to a better understanding of the role of somatosensory feedback in balance control.
It could also lead to advancements in spinal cord injury treatment because the research suggested that activating somatosensory neurons can improve spinal neural networks' function below the spinal cord damage site.
Cats Who Worked Together
Although genetically modified mouse models have recently become dominant in research on neural control of locomotion, the cat model has a significant advantage.
Mice remain crouched when they move, which means they are less likely to have balance issues even if somatosensory feedback fails.
On the other hand, humans and cats cannot maintain balance or even move if sensory information about limb motion is lost.
This suggests that larger species, such as cats and humans, may have a different spinal neural network organization controlling locomotion than rodents.
Georgia Tech collaborated with researchers from the University of Sherbrooke in Canada and Drexel University in Philadelphia to learn more about how sensory neuron signals the coordinated movement of the four legs.
The Sherbrooke lab trained cats to walk on a treadmill at a pace consistent with human gait before stimulating their sensory nerves with electrodes.
The researchers concentrated on the sensory nerve that connects the top of the foot to the spinal cord.
Researchers electrically stimulated this nerve to simulate hitting an obstacle and observed how the cats stumbled and rectified their actions as a result.
Stimulations were used at four different points during the walking cycle: mid-stance, stance-to-swing change, mid-swing, and swing-to-stance transition.
They discovered that the stimulation increased activity in muscles that flex the knee and hip joints, joint flexion, toe height, step length, and step duration of the stimulated limb during the mid-swing and the stance-to-swing transition.
Georgia Tech and Drexel University researchers are using observations from these Canadian lab experiments to develop a computational model of the cat's musculoskeletal and spinal neural control systems.
The data gathered are used to compute somatosensory signals related to length and velocity, and produced a force on muscles, as well as pressure on the skin in all limbs.
This information generates motion sensations in the animal's spinal cord and helps the spinal neuronal networks coordinate interlimb movement.
"We need to understand how the entire system works to help treat any disease," Prilutsky said.
"That was one reason why this study was performed, so we could comprehend how the spinal channels coordinate muscle activity and create a realistic computational model of spinal control of locomotion. This will help us understand how the spinal cord regulates locomotion," he added via Newswise.
