web analytics

Spinal Circuit for Light Touch and Fine Motor Control Helps You Walk on Ice

walk on ice

Image credit: Peter Burnett/iStockphoto

At present, many residents living in Northern Hemisphere are having their coldest days in winter and some of them are good at walking on top of ice. According to the latest study done by the scientists from the Salk Institute for Biological Studies in California, it is suggested that apart from the normal mechanisms with which the body keeps upright, they found some neurons on the spine being clustered in a “mini-brain”, which are capable of combining sensory information and motor commands in order to take small, unconscious movements of the foot to achieve better balancing effect. This research has been published in the recent edition of Cell .

As Martyn Goulding, the senior author said, when people stood and walked, touch sensors on the soles of their feet could trace subtle changes in regard to pressure and movement. At first such sensors send signals to their spinal cord and then were relayed to the brain. The current study was just like opening kind of a black box, because, even at this moment, scientists were uncertain about the way in which these signals were encoded or processed in the spinal cord. Furthermore, they were also not clear how this touch information was associated to other sensory information in terms of movement and posture control.

To keep balance while walking upright, the brain is able to process a lot of sensory information. For example, a sense of touch could give out information concerning amount of traction and wind speed, fluid in the ear could offer a sense of orientation related with the ground, and sight could make people know about obstacles on the ground, something like upcoming hill or the terrain change, and even muscles could release information regarding their positions. But, up to now, it has not been really understood about the neural pathways that interpret so much information to make it possible for the body to make movements in a controlled way.

In this study, scientists succeeded in mapping out the neural circuitry and discovered that the main factor related to combining sensory information with the necessary corresponding motor function was a group of sensory neurons on the spinal cord connected with the RORα neurons that was bridged to the motor region of the brain. Therefore, it acted as a “mini-brain”, which could help maintain balance in difficult situations.

Steeve Bourane, the lead author went on; it was such neurons that were responsible for integrating all the information to let feet know how to move. When people stood on a slippery surface for a long period of time, they would observe that their calf muscles became stiff, but they might not notice they were using them. It is accepted that our body is always on autopilot, which could enable subtle corrections while making you free to handle other higher-level tasks.

In the experiment to disable this circuitry in mice, it showed that although they could still walk under normal circumstance, when the terrain became more difficult, they could not able to make the small foot adjustments in the way that they would keep balance and walk properly. It is very important to know better about this pathway as well as other mechanisms with which the brain could process sensory information, because it would be much helpful in improving therapies provided for patients with spinal cord disease or trauma.

When talking of their current research, Goulding said, one of the main questions in neuroscience was to understand the way in which the brain built up a sensory percept and turned it into an action. What they were doing now was to offer a better view of neural pathways and processes, which underlie the control of movement and how the body senses its environment. They were sure that some real change would take place in the field as their research was still going on.

Journal reference: Bourane, Steeve, et al. “Identification of a Spinal Circuit for Light Touch and Fine Motor Control.” Cell 160.3 (2015): 503-515.

You May Also Like:

Can’t Sleep? Turn on the Sleep Switch!
Marijuana Abuse Hampers the Brain’s Response to Dopamine
Your Brain on Coffee
Why Do You Have Dreams?